From 4e6b7a665b8bccc5f5d05ab4013f56390a65dda7 Mon Sep 17 00:00:00 2001
From: Daniel Cherubini <daniel@cherubini.casa>
Date: Fri, 20 Mar 2026 14:07:58 +0100
Subject: [PATCH] fix: make bash tool description parameter optional

The description parameter on the bash tool is required but some models
(especially smaller/local models) don't always include it in tool calls,
causing "Invalid input: expected string, received undefined" errors that
loop indefinitely. Make it optional and fall back to the command string
when not provided.

Fixes #13146
---
 packages/opencode/src/tool/bash.ts | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/packages/opencode/src/tool/bash.ts b/packages/opencode/src/tool/bash.ts
index 50ae4abac8de..916ea88d9d1b 100644
--- a/packages/opencode/src/tool/bash.ts
+++ b/packages/opencode/src/tool/bash.ts
@@ -73,9 +73,11 @@ export const BashTool = Tool.define("bash", async () => {
         .string()
         .describe(
           "Clear, concise description of what this command does in 5-10 words. Examples:\nInput: ls\nOutput: Lists files in current directory\n\nInput: git status\nOutput: Shows working tree status\n\nInput: npm install\nOutput: Installs package dependencies\n\nInput: mkdir foo\nOutput: Creates directory 'foo'",
-        ),
+        )
+        .optional(),
     }),
     async execute(params, ctx) {
+      const description = params.description ?? params.command
       const cwd = params.workdir || Instance.directory
       if (params.timeout !== undefined && params.timeout < 0) {
         throw new Error(`Invalid timeout value: ${params.timeout}. Timeout must be a positive number.`)
@@ -182,7 +184,7 @@ export const BashTool = Tool.define("bash", async () => {
       ctx.metadata({
         metadata: {
           output: "",
-          description: params.description,
+          description: description,
         },
       })
 
@@ -192,7 +194,7 @@ export const BashTool = Tool.define("bash", async () => {
           metadata: {
             // truncate the metadata to avoid GIANT blobs of data (has nothing to do w/ what agent can access)
             output: output.length > MAX_METADATA_LENGTH ? output.slice(0, MAX_METADATA_LENGTH) + "\n\n..." : output,
-            description: params.description,
+            description: description,
           },
         })
       }
@@ -257,11 +259,11 @@ export const BashTool = Tool.define("bash", async () => {
       }
 
       return {
-        title: params.description,
+        title: description,
         metadata: {
           output: output.length > MAX_METADATA_LENGTH ? output.slice(0, MAX_METADATA_LENGTH) + "\n\n..." : output,
           exit: proc.exitCode,
-          description: params.description,
+          description: description,
         },
         output,
       }