Check Browser Performance

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

The description confirms it is a read-only operation (consistent with readOnlyHint annotation) and adds context that it does not auto-record bugs. However, it could mention any potential side effects or performance overhead, though none expected.

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?

Concise three-sentence description. First sentence front-loads purpose, subsequent sentences provide usage context. No wasted words.

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 no parameters and an output schema, the description provides sufficient context: what metrics are read, when to use it, and when to use an alternative tool. Covers all key aspects.

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?

No parameters exist, so schema coverage is 100%. The description adds meaning by listing the specific metrics returned, which helps the agent understand the output.

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 tool reads raw performance metrics from the browser's Performance API, listing specific metrics. It distinguishes from sibling tool 'record_bug' by noting that performance auditing is owned by Lighthouse.

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?

Provides explicit guidance on when to use this tool versus record_bug: only call record_bug if performance issues materially block users. No unnecessary use of this tool for auto-recording.

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