analyze_page_speed

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

Beyond annotations (readOnlyHint=true, destructiveHint=false), the description adds important behavioral details: it takes 10-30 seconds, returns specific metrics (score, lab CWV, CrUX data, opportunities), and explains that the speed is normal. This fully informs the agent about the tool's execution behavior.

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 concise and well-structured. It starts with the core purpose, then details the output, followed by usage advice and timing. Every sentence adds value without redundancy, making it easy to parse.

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 the tool's complexity (multiple metrics, two strategies, timing), the description is complete. It covers what the tool returns (score, lab CWV, CrUX, opportunities), when to use it (ad final_urls), and the normal execution time. With an output schema likely present, the description provides sufficient context for the agent to understand the tool's capabilities.

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?

With 0% schema description coverage, the description adds crucial meaning: 'url' is a landing page URL (implied), and 'strategy' is explained with valid values 'mobile' or 'desktop' and default 'mobile'. This compensates for the lack of schema descriptions and guides correct usage.

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 explicitly states 'Run PageSpeed Insights for a landing page' and distinguishes it from siblings like 'landing_page_analysis' and other action-oriented tools. It identifies the tool as a performance analysis tool, which is clear and specific.

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 provides clear guidance: 'Use on ad final_urls' and explains the reasoning. It also mentions the two strategy options ('mobile' default, 'desktop'). It does not explicitly state when not to use or compare to alternatives, but the context is sufficient for an agent to decide.

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