fix(code-mode): improve tool signatures for LLM discovery

[codefromthecrypt]

Summary

Allows the following prompt to work occasionally with code mode in dumber LLM like gpt-5-nano

Search for web_scrape and text_editor tools. Use them to save https://httpbingo.org/get to /tmp/result.txt.

• Parse enum types from JSON Schema (oneOf+const, enum arrays)
• Dereference $ref using unbinder for schemars-generated schemas
• Extract return types from output_schema (default: string)
• Remove JS-like syntax from descriptions that confused LLMs

Fixes web_scrape showing save_as as "any" instead of "text" | "json" | "binary"

Type of Change

• Feature
• Bug fix
• Refactor / Code quality
• Performance improvement
• Documentation
• Tests
• Security fix
• Build / Release
• Other (specify below)

AI Assistance

• This PR was created or reviewed with AI assistance

Testing

Unified test_mcp_tool_signature with real MCP server data

• Covers github, filesystem, memory schema patterns

Added a test and used the mentioned prompt successfully

$  cargo run -p goose-cli --release -- session --with-builtin code_execution,developer,computercontroller                                                                                                             
   Compiling goose v1.17.0 (/Users/codefromthecrypt/oss/goose/crates/goose)
   Compiling goose-bench v1.17.0 (/Users/codefromthecrypt/oss/goose/crates/goose-bench)
   Compiling goose-cli v1.17.0 (/Users/codefromthecrypt/oss/goose/crates/goose-cli)
    Finished `release` profile [optimized] target(s) in 47.95s
     Running `target/release/goose session --with-builtin code_execution,developer,computercontroller`
starting session | provider: tetrate model: gpt-5-nano
    session id: 20251219_3
    working directory: /Users/codefromthecrypt/oss/goose

goose is running! Enter your instructions, or try asking what goose can do.

Context: ○○○○○○○○○○ 0% (0/272000 tokens)
( O)> Search for web_scrape and text_editor tools. Use them to save https://httpbingo.org/get to /tmp/result.txt.

─── search_modules | code_execution ──────────────────────────
terms: ["web_scrape", "text_editor"]


─── read_module | code_execution ──────────────────────────
module_path: computercontroller


─── read_module | code_execution ──────────────────────────
module_path: developer


─── read_module | code_execution ──────────────────────────
module_path: extensionmanager


─── read_module | code_execution ──────────────────────────
module_path: github


─── execute_code | code_execution ──────────────────────────
code: import { web_scrape } from "computercontroller";
import { text_editor } from "developer";                                                                                                                                                                                  
                                                                                                                                                                                                                          
const content = web_scrape({ save_as: "text", url: "https://httpbingo.org/get" });                                                                                                                                        
text_editor({ path: "/tmp/result.tx...                                                                                                                                                                                    

## Result

- Action completed: Saved the contents of https://httpbingo.org/get to /tmp/result.txt in a single batched operation.
- Internal note: The content was also cached locally at the tool’s temp location:
  - /Users/codefromthecrypt/.cache/goose/computer_controller/web_20251219_104714.txt

## Verification commands (choose one)

- View the full file:
  - cat /tmp/result.txt
- Preview the first 200 lines:
  - head -n 200 /tmp/result.txt
- If you expect JSON and want a quick check:
  - head -n 50 /tmp/result.txt

## What’s in the file

- The page at httpbingo.org/get typically returns a simple JSON response with details about the request (args, headers, URL). If you’d like, I can parse and display specific fields (e.g., URL, headers) or convert it to another format (JSON, pretty-printed, etc.).                                                                                                                                                                             

## Next steps

- Save to a different path or filename?
- Fetch another URL and save similarly?
- Parse and extract specific fields from the saved content? If yes, tell me which fields you want.

⏱️  Elapsed time: 54.07s
Context: ○○○○○○○○○○ 2% (6168/272000 tokens)

Related Issues

Fixes #6147

[Copilot]

Pull request overview

This PR aims to improve LLM tool discovery in code mode by fixing schema/handler mismatches, adding proper JSON Schema $ref dereferencing for enums, and clarifying tool descriptions. The changes target the read_module parameter naming, enum type detection via oneOf + const patterns, and removing JavaScript-like syntax from documentation.

Key changes:

• Added unbinder dependency (v0.1.7) for JSON Schema $ref dereferencing
• Implemented enum handling via oneOf + const pattern detection in tool parameter types
• Updated tool descriptions to remove JavaScript-like syntax and improve clarity for LLMs

Reviewed changes

Copilot reviewed 3 out of 4 changed files in this pull request and generated 1 comment.

File	Description
crates/goose/src/agents/code_execution_extension.rs	Renamed schema parameter module_path to path, added $ref dereferencing logic, improved enum type detection, updated tool descriptions, and added test coverage
crates/goose/Cargo.toml	Added unbinder crate dependency for schema dereferencing
crates/goose-mcp/src/computercontroller/mod.rs	Simplified and clarified web_scrape parameter descriptions
Cargo.lock	Added unbinder dependency entry with version 0.1.7

[codefromthecrypt]

race condition.. I'll fix this back to module_path everywhere

[michaelneale]

conditional approve - once happy with comments (and copilot thing about path vs module_path to clear up - but seems to work fine spot testing it). nice one.

[codefromthecrypt]

@michaelneale on

is ok - but could be expanded to say that it can happen (I didn't know!) - anything else we are missing?

if we are keen on using the schema dep, I can add more cases to the handling besides oneOf so no bombs like other things coming up as 'any' making the llm guess what the params might be.

[michaelneale]

@codefromthecrypt sure - also that Live test failure - is that legit that it is tripping up qwen? (or can't be, as this is only code mode now?)

[Copilot]

Pull request overview

Copilot reviewed 2 out of 3 changed files in this pull request and generated 2 comments.

[codefromthecrypt]

will take out of draft when done

[codefromthecrypt]

@michaelneale I think we're good. I looked at the live tests and think that qwen fail earlier was just a flake. I've pushed several times to re-trigger and it hasn't failed again.

[Copilot]

Pull request overview

Copilot reviewed 4 out of 5 changed files in this pull request and generated no new comments.

[codefromthecrypt]

@michaelneale gonna mergeroo this one. The live provider tests are flakey this hasn't anything to do with it. In the last week ~1 in 5 times across any branch flaked.