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

The description states the core behavior: it crawls a website, performs technical SEO checks, returns prioritized findings with fixes. Since annotations already are safe (destructiveHint=false), this adds useful detail and clearly sets expectations about the activity. However, it does not discuss rate limits, negative side effects on the target, or authorization requirements beyond what the target parameter mentions, so it is adequate but not deeply transparent.

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 tight sentences: the first states the action and the full checklist, and the second states the result. There's no filler, no repetition of schema details, and the content is front-loaded. The comma-separated enumeration is efficient for an agent 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?

For a complex auditing tool, the description covers the core domain and enumerates the full audit surface. With an output schema present and full parameter documentation in the schema, this is nearly sufficient. The only notable gap is not explicitly naming alternatives (e.g., audit_full) or how to decide between them, but that's a minor context gap.

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 input schema already provides complete descriptions for all three parameters, including the default values, allowed language enum, and maxPages bounds. The description's text doesn't need to repeat this and simply gives context for 'target' by saying 'Crawl a site'. At 100% schema coverage, the description adds almost no parameter-level value, so the baseline score of 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 opens with a specific verb and resource ('Crawl a site and audit technical SEO') and enumerates a detailed set of concrete checks (crawlability, indexation, titles/meta, canonical, structured data, broken links, redirect chains, AI-crawler policy). This clearly defines the tool's domain and distinguishes it from sibling tools like audit_security or audit_accessibility, making the intended scope unambiguous.

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 clearly establishes when to use it: for a technical SEO audit, including a specific set of sub-audits. It does not explicitly name alternatives or exclusion criteria, but the scoping language is clear enough that an agent can match a user request to this tool versus the other audit-focused siblings.

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