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

Annotations already cover the safety profile (readOnlyHint=true, openWorldHint=true, destructiveHint=false), and the description adds real behavioral context beyond them: it follows sitemap indexes and .gz files, and surfaces lastmod, priority and changefreq. It stops short of describing pagination or failure behavior for sites without a sitemap.

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 first two sentences restate the title and the tool name ('URLs listed in a website's sitemap. Extract sitemap URLs.') before reaching the useful content, so roughly a third of the text is redundant, though the remaining content is front-loaded and dense.

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?

With no output schema, the description usefully names the returned fields (lastmod, priority, changefreq) and the sitemap-traversal behavior. Missing only edge-case guidance (no sitemap present, gzip failure) for a fully complete picture of a simple three-parameter read tool.

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 url, limit and contains with examples. The description only gestures at 'Filter by text' (contains) and mentions lastmod/priority/changefreq, which are return fields rather than parameters, so it adds little beyond the 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?

States a specific verb+resource ('Extract sitemap URLs... Get all URLs of a website from its sitemaps') and adds mechanics (found via robots.txt, follows sitemap indexes and .gz files) that clearly separate it from siblings like extract_links, robots_txt_check, or seo_audit.

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?

Usage is implied by the resource ('from its sitemaps, found via robots.txt'), so an agent can infer this is the sitemap-discovery tool, but there is no explicit when-to-use/when-not statement or named alternative for related needs such as crawling links or auditing SEO.

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