Run Lighthouse Audit

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

Annotations declare readOnlyHint=true and openWorldHint=true, so the agent knows this is a safe read operation. The description adds 'comprehensive' but doesn't disclose behavioral traits like the fact that it runs multiple categories, the time it takes, or that it may be slower than targeted audits. With annotations covering safety, the description adds minimal behavioral context beyond the word 'comprehensive'.

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 a single sentence with no waste. It's front-loaded with the verb and resource. It could be slightly more informative, but it's concise and to the point.

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?

The tool has an output schema (not shown) and 4 parameters with 75% schema coverage. The description is minimal but the schema and annotations carry some weight. However, given the complexity of a Lighthouse audit (multiple categories, device emulation, throttling), the description could explain what 'comprehensive' means and how it relates to the sibling tools. It's adequate but not complete.

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 description coverage is 75%, so most parameters are documented in the schema. The description doesn't add any parameter-specific meaning beyond what the schema provides. The 'categories' parameter has an enum with 'agentic-browsing' which is unusual, but the description doesn't explain it. Baseline 3 is appropriate since the schema does most of the work.

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 states a specific verb ('Run') and resource ('Lighthouse audit'), and the title clarifies it's a website audit. It's clear what the tool does, though it doesn't explicitly differentiate from siblings like get_performance_score or get_accessibility_score, which are more specific. The description is broad but not misleading.

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 usage for running a comprehensive audit, but it doesn't explicitly state when to use this tool versus the more specific sibling tools (e.g., get_performance_score, get_accessibility_score). It doesn't mention alternatives or exclusions. The context signals show many sibling tools that are more targeted, so the description should guide the agent on when to choose this comprehensive audit over those.

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