psi_opportunities

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

Annotations already declare readOnlyHint=true and destructiveHint=false. Description adds behavioral context: uses lab-only data, returns specific audits, defaults to mobile. No contradictions. Could mention potential quota limits or output size.

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?

Single sentence is efficient and front-loaded. Each clause adds distinct value (lab data, audit types, alternative tools, default strategy). Could be slightly restructured for readability.

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?

Purpose and parameters are well-covered. However, with no output schema, the description only vaguely describes return types ('estimated load-time savings', 'severity grades'). Lacks concrete output structure for an agent to parse programmatically.

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 descriptions for both url and strategy. Description only adds that strategy defaults to mobile, confirming existing schema info. No additional semantic depth beyond schema.

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?

Description clearly states the tool runs PageSpeed Insights lab data and returns two specific audit types (opportunity savings, SEO severity). It distinguishes from siblings by emphasizing lab-only data and naming alternatives (crux_snapshot, crux_history) for field 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?

Explicitly states that this tool uses lab data only and recommends field-data alternatives (crux_snapshot/crux_history). Also notes default mobile strategy. Could be more explicit about when to prefer this over sibling psi_analyze.

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