cpp_build

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the full transparency burden. It discloses that the build runs in the background, returns a job_id immediately, and that compiler errors will be structured (file, line, code, message). It doesn't mention potential side effects (e.g., generated files) or failure modes, but it gives a clear behavioral model for an async job.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

A single, well-structured sentence front-loads the verb 'Compile', states the resource, and immediately provides the key workflow (returns job_id, poll job_status). No filler or redundancy.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a build tool with 5 optional parameters, no output schema, and no annotations, the description covers the essential workflow: start async build, get job_id, poll status for structured errors. It could additionally mention timeout behavior or success output, but the schema documents timeout_seconds, and the overall usage pattern is clear.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the schema already explains all five parameters (target, platform, extra_args, configuration, timeout_seconds) with defaults where applicable. The description adds no per-parameter detail, which is fine given the schema's completeness. Baseline of 3 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description specifies the exact action ('Compile the project with UnrealBuildTool') and the asynchronous nature (background job). It clearly distinguishes this from sibling tools like job_status or cpp_class_create by stating it returns a job_id for polling, making it obvious this is the build initiation tool.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

It clearly indicates when to use it (to compile the project) and that you should poll job_status afterward. However, it does not explicitly mention when not to use it or alternatives (e.g., blueprint_compile for Blueprint scripts), though the context of UBT implies C++ only.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.