pix_capture_timing

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

Annotations already indicate readOnlyHint=false, destructiveHint=false, and idempotentHint=false. The description adds 'CPU/GPU timeline' and the launch/attach scope, which is useful, but it doesn't disclose operational behavior such as creating an output file, potentially long-running capture, requiring an active connection, or the effects of toggles like no_cpu_samples or no_gpu_timings.

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?

The description is a single, front-loaded sentence with no filler; the core action and resource are immediately clear. However, it is so terse that it omits essential operational context, which prevents a perfect score.

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 13-parameter capture tool with 0% schema coverage, this one-liner is far from complete. It fails to explain target selection, duration, sampling rate, callstack/timing toggles, timeout, working directory, and remote execution, leaving a large operational gap despite the presence of an output schema.

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 0%, and the description does not compensate for it. None of the 13 parameters, including the required output_file or key fields like executable, process_id, duration_ms, remote, and working_directory, are explained. This leaves an agent with almost no semantic guidance for constructing arguments.

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 clearly states the action ('Record a PIX timing capture'), the object ('CPU/GPU timeline'), and the target ('launched or attached app'). However, it doesn't explicitly differentiate this from sibling capture tools like pix_capture_app or pix_capture_attached_process, so full sibling distinction is missing.

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?

There is no explicit guidance on when to use this tool versus alternatives. The phrase 'launched or attached app' implies two target modes, but it doesn't explain how to choose between launching, attaching, or using pix_capture_programmatic or other capture tools.

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