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

Annotations already declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds valuable behavioral context beyond annotations: it flags legal pages with legalPage:true, applies a -25 significance penalty, and explains that robots.txt-blocked pages are silently dropped when excludeDisallowed is true. It does not contradict annotations.

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 well-structured and front-loaded with the core purpose, followed by filtering behavior and legal-page handling. It is slightly long but every sentence adds meaningful context, and the legal-page explanation earns its place because it clarifies a non-obvious behavior.

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 discovery tool with 9 parameters and no output schema, the description covers the key behaviors an agent needs: ranking, filtering, legal-page handling, and robots.txt behavior. It does not describe the exact return format, but the absence of an output schema makes that a minor gap given the rich parameter documentation.

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 100%, so the schema already documents all 9 parameters. The description adds context for the legalPages parameter and the significance penalty, but most parameter semantics are already fully covered by the schema. 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 states a specific verb ('Discovers and ranks'), a clear resource ('URLs from a domain's XML sitemaps'), and the intended use case ('find the most significant pages... before analyzing them'). It also distinguishes itself from sibling tools by focusing on sitemap discovery rather than test execution or management.

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 explicitly says when to use this tool ('before analyzing them') and provides clear filtering guidance, including how to handle legal/policy pages with the legalPages filter. It also names the alternative behavior for policy-coverage audits ('only'), giving the agent explicit routing context.

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