Page Performance Check

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

Annotations (readOnlyHint: true) indicate no destructive side effects. The description adds context by listing specific metrics measured and the type of output (grade with recommendations). This aligns with annotations and provides useful behavioral details beyond what annotations convey.

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 sentences, front-loading the key actions (measure, returns) without waste. Every sentence adds unique value; concise and efficient.

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 a single parameter and no output schema, the description adequately explains the tool's purpose and output (performance grade with recommendations). It could benefit from mentioning grading scale or units, but is sufficiently complete for the low complexity.

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?

The sole parameter 'url' is described in the input schema as 'Website URL to check'. The description does not add any extra meaning or format requirements beyond the schema. With 100% schema coverage, baseline 3 is appropriate.

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 measures TTFB, load time, page weight, redirect chain, compression, and cache headers, and returns a performance grade with recommendations. It distinguishes itself from sibling tools like check_dns and check_ssl by focusing on page performance metrics.

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 implies use for evaluating page performance but does not explicitly state when to use this tool over siblings (e.g., vs. audit_site). No exclusions or alternatives are provided, relying on natural distinction from context.

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