start_profiling

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

With no annotations provided, the description carries full responsibility. It discloses that recording runs in background, returns immediately, has a 5-minute safety limit, and auto-stops. This provides sufficient behavioral context, though it could mention what the tool returns (immediate indicator) and error scenarios.

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 two paragraphs with a clear workflow. It front-loads the main action. Some redundancy (e.g., 'safety limit' mentioned twice) but overall efficient. Could be slightly tighter without losing meaning.

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?

Given 5 parameters and no output schema, the description covers the tool's purpose, workflow, and safety limit. It explains that recording is manual and results come via stop_profiling. Missing details on return type or error handling, but adequate for effective use.

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 coverage is 100%, with all 5 parameters described. The description adds minimal extra context beyond the schema (e.g., max_duration default explanation). Baseline of 3 is appropriate since the description does not significantly augment parameter understanding.

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 'Start recording an Instruments trace and return immediately.' It identifies the verb ('start recording') and resource ('Instruments trace'), distinguishing it from siblings like stop_profiling or specific profiling tools. The workflow clarifies its role.

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?

The description explains a recommended workflow (start_profiling → user interaction → stop_profiling) and mentions when to use (for profiling real user interactions). However, it does not explicitly exclude alternatives like dedicated profiling tools (profile_cpu, etc.) or discuss when not to use.

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