diff --git a/docs/src/components/BuiltinAgents.mdx b/docs/src/components/BuiltinAgents.mdx
index 590d5a512..7303c90ab 100644
--- a/docs/src/components/BuiltinAgents.mdx
+++ b/docs/src/components/BuiltinAgents.mdx
@@ -13,4 +13,4 @@ import { LinkCard } from '@astrojs/starlight/components';
 <LinkCard title="agent interpreter" description="run code interpreters for Python, Math. Use this agent to ground computation questions." href="/genaiscript/reference/scripts/system#systemagent_interpreter" />
 <LinkCard title="agent planner" description="generates a plan to solve a task" href="/genaiscript/reference/scripts/system#systemagent_planner" />
 <LinkCard title="agent user_input" description="ask user for input to confirm, select or answer the question in the query. The message should be very clear and provide all the context." href="/genaiscript/reference/scripts/system#systemagent_user_input" />
-<LinkCard title="agent web-search" description="search the web to accomplish tasks." href="/genaiscript/reference/scripts/system#systemagent_web" />
+<LinkCard title="agent web" description="search the web to accomplish tasks." href="/genaiscript/reference/scripts/system#systemagent_web" />
diff --git a/docs/src/components/BuiltinTools.mdx b/docs/src/components/BuiltinTools.mdx
index 7edf0b168..155e4c260 100644
--- a/docs/src/components/BuiltinTools.mdx
+++ b/docs/src/components/BuiltinTools.mdx
@@ -13,7 +13,6 @@ import { LinkCard } from '@astrojs/starlight/components';
 <LinkCard title="git_branch_default" description="Gets the default branch using git." href="/genaiscript/reference/scripts/system#systemgit" />
 <LinkCard title="git_branch_current" description="Gets the current branch using git." href="/genaiscript/reference/scripts/system#systemgit" />
 <LinkCard title="git_branch_list" description="List all branches using git." href="/genaiscript/reference/scripts/system#systemgit" />
-<LinkCard title="git_diff" description="Computes file diffs using the git diff command. If the diff is too large, it returns the list of modified/added files." href="/genaiscript/reference/scripts/system#systemgit" />
 <LinkCard title="git_list_commits" description="Generates a history of commits using the git log command." href="/genaiscript/reference/scripts/system#systemgit" />
 <LinkCard title="git_status" description="Generates a status of the repository using git." href="/genaiscript/reference/scripts/system#systemgit" />
 <LinkCard title="git_last_tag" description="Gets the last tag using git." href="/genaiscript/reference/scripts/system#systemgit" />
diff --git a/docs/src/content/docs/reference/scripts/system.mdx b/docs/src/content/docs/reference/scripts/system.mdx
index e63143ef2..d85eac8b9 100644
--- a/docs/src/content/docs/reference/scripts/system.mdx
+++ b/docs/src/content/docs/reference/scripts/system.mdx
@@ -390,7 +390,7 @@ system({
 const model = env.vars.agentWebSearchModel
 
 defAgent(
-    "web-search",
+    "web",
     "search the web to accomplish tasks.",
     `Your are a helpful LLM agent that can use web search.
     Answer the question in QUERY.`,
@@ -1080,7 +1080,6 @@ Tools to query a git repository.
 -  tool `git_branch_default`: Gets the default branch using git.
 -  tool `git_branch_current`: Gets the current branch using git.
 -  tool `git_branch_list`: List all branches using git.
--  tool `git_diff`: Computes file diffs using the git diff command. If the diff is too large, it returns the list of modified/added files.
 -  tool `git_list_commits`: Generates a history of commits using the git log command.
 -  tool `git_status`: Generates a status of the repository using git.
 -  tool `git_last_tag`: Gets the last tag using git.
@@ -1113,58 +1112,6 @@ defTool("git_branch_list", "List all branches using git.", {}, async () => {
     return await git.exec("branch")
 })
 
-defTool(
-    "git_diff",
-    "Computes file diffs using the git diff command. If the diff is too large, it returns the list of modified/added files.",
-    {
-        type: "object",
-        properties: {
-            base: {
-                type: "string",
-                description: "Base branch, ref, commit sha to compare against.",
-            },
-            head: {
-                type: "string",
-                description:
-                    "Head branch, ref, commit sha to compare. Use 'HEAD' to compare against the current branch.",
-            },
-            staged: {
-                type: "boolean",
-                description: "Compare staged changes",
-            },
-            nameOnly: {
-                type: "boolean",
-                description: "Show only file names",
-            },
-            paths: {
-                type: "array",
-                description: "Paths to compare",
-                items: {
-                    type: "string",
-                    description: "File path or wildcard supported by git",
-                },
-            },
-            excludedPaths: {
-                type: "array",
-                description: "Paths to exclude",
-                items: {
-                    type: "string",
-                    description: "File path or wildcard supported by git",
-                },
-            },
-        },
-    },
-    async (args) => {
-        const { context, ...rest } = args
-        const res = await git.diff({
-            llmify: true,
-            ...rest,
-        })
-        return res
-    },
-    { maxTokens: 20000 }
-)
-
 defTool(
     "git_list_commits",
     "Generates a history of commits using the git log command.",
diff --git a/package.json b/package.json
index f896fc556..797fd1681 100644
--- a/package.json
+++ b/package.json
@@ -13,6 +13,7 @@
         "setup": "git submodule update --init --recursive",
         "setup:az": "curl -sL https://aka.ms/InstallAzureCLIDeb | sudo bash",
         "setup:bicep": "az bicep upgrade",
+        "az:login": "az login --scope api://trapi/.default",
         "install:playwright": "yarn install playwright --with-deps",
         "install:force": "rm yarn.lock && yarn install && yarn --cwd docs install:force && yarn --cwd slides install:force && yarn gen:licenses",
         "compile-ext": "yarn --cwd packages/core run prompts:bundle && yarn --cwd packages/vscode run compile",
diff --git a/packages/core/src/anthropic.ts b/packages/core/src/anthropic.ts
index 37d40769d..84cc6dfce 100644
--- a/packages/core/src/anthropic.ts
+++ b/packages/core/src/anthropic.ts
@@ -433,7 +433,7 @@ const completerFactory = (
 
         trace.appendContent("\n\n")
         trace.itemValue(`🏁 finish reason`, finishReason)
-        if (usage) {
+        if (usage?.total_tokens) {
             trace.itemValue(
                 `🪙 tokens`,
                 `${usage.total_tokens} total, ${usage.prompt_tokens} prompt, ${usage.completion_tokens} completion`
diff --git a/packages/core/src/chat.ts b/packages/core/src/chat.ts
index 9a5fec966..11a095797 100644
--- a/packages/core/src/chat.ts
+++ b/packages/core/src/chat.ts
@@ -79,6 +79,7 @@ import {
     serializeLogProb,
     topLogprobsToMarkdown,
 } from "./logprob"
+import { uniq } from "es-toolkit"
 
 export function toChatCompletionUserMessage(
     expanded: string,
@@ -892,8 +893,15 @@ export async function executeChatSession(
 
     try {
         trace.startDetails(`🧠 llm chat`)
-        if (toolDefinitions?.length)
+        if (toolDefinitions?.length) {
             trace.detailsFenced(`🛠️ tools`, tools, "yaml")
+            const toolNames = toolDefinitions.map(({ spec }) => spec.name)
+            const duplicates = uniq(toolNames).filter(
+                (name, index) => toolNames.lastIndexOf(name) !== index
+            )
+            if (duplicates.length)
+                throw new Error(`duplicate tools: ${duplicates.join(", ")}`)
+        }
         let genVars: Record<string, string>
         while (true) {
             stats.turns++
diff --git a/packages/core/src/genaisrc/system.agent_web.genai.mjs b/packages/core/src/genaisrc/system.agent_web.genai.mjs
index cb87e88a5..9963189b3 100644
--- a/packages/core/src/genaisrc/system.agent_web.genai.mjs
+++ b/packages/core/src/genaisrc/system.agent_web.genai.mjs
@@ -5,7 +5,7 @@ system({
 const model = env.vars.agentWebSearchModel
 
 defAgent(
-    "web-search",
+    "web",
     "search the web to accomplish tasks.",
     `Your are a helpful LLM agent that can use web search.
     Answer the question in QUERY.`,
diff --git a/packages/core/src/genaisrc/system.git.genai.mjs b/packages/core/src/genaisrc/system.git.genai.mjs
index b753cd36e..1fb5fbeea 100644
--- a/packages/core/src/genaisrc/system.git.genai.mjs
+++ b/packages/core/src/genaisrc/system.git.genai.mjs
@@ -25,58 +25,6 @@ defTool("git_branch_list", "List all branches using git.", {}, async () => {
     return await git.exec("branch")
 })
 
-defTool(
-    "git_diff",
-    "Computes file diffs using the git diff command. If the diff is too large, it returns the list of modified/added files.",
-    {
-        type: "object",
-        properties: {
-            base: {
-                type: "string",
-                description: "Base branch, ref, commit sha to compare against.",
-            },
-            head: {
-                type: "string",
-                description:
-                    "Head branch, ref, commit sha to compare. Use 'HEAD' to compare against the current branch.",
-            },
-            staged: {
-                type: "boolean",
-                description: "Compare staged changes",
-            },
-            nameOnly: {
-                type: "boolean",
-                description: "Show only file names",
-            },
-            paths: {
-                type: "array",
-                description: "Paths to compare",
-                items: {
-                    type: "string",
-                    description: "File path or wildcard supported by git",
-                },
-            },
-            excludedPaths: {
-                type: "array",
-                description: "Paths to exclude",
-                items: {
-                    type: "string",
-                    description: "File path or wildcard supported by git",
-                },
-            },
-        },
-    },
-    async (args) => {
-        const { context, ...rest } = args
-        const res = await git.diff({
-            llmify: true,
-            ...rest,
-        })
-        return res
-    },
-    { maxTokens: 20000 }
-)
-
 defTool(
     "git_list_commits",
     "Generates a history of commits using the git log command.",
diff --git a/packages/core/src/llms.json b/packages/core/src/llms.json
index 537459a40..46b17b071 100644
--- a/packages/core/src/llms.json
+++ b/packages/core/src/llms.json
@@ -71,10 +71,10 @@
             "prediction": false,
             "bearerToken": true,
             "aliases": {
-                "large": "gemini-2.0-flash-exp",
+                "large": "gemini-1.5-flash-latest",
                 "small": "gemini-1.5-flash-latest",
-                "vision": "gemini-2.0-flash-exp",
-                "long": "gemini-2.0-flash-exp",
+                "vision": "gemini-1.5-flash-latest",
+                "long": "gemini-1.5-flash-latest",
                 "reasoning": "gemini-2.0-flash-thinking-exp-1219",
                 "reasoning_small": "gemini-2.0-flash-thinking-exp-1219",
                 "embeddings": "text-embedding-004"
diff --git a/packages/core/src/openai.ts b/packages/core/src/openai.ts
index 16592161f..73b324cdc 100644
--- a/packages/core/src/openai.ts
+++ b/packages/core/src/openai.ts
@@ -399,7 +399,7 @@ export const OpenAIChatCompletion: ChatCompletionHandler = async (
     trace.appendContent("\n\n")
     if (responseModel) trace.itemValue(`model`, responseModel)
     trace.itemValue(`🏁 finish reason`, finishReason)
-    if (usage) {
+    if (usage?.total_tokens) {
         trace.itemValue(
             `🪙 tokens`,
             `${usage.total_tokens} total, ${usage.prompt_tokens} prompt, ${usage.completion_tokens} completion`