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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is communicated. The description adds valuable behavioral detail: it finds sitemaps via multiple methods, handles index sitemaps, validates specific fields, flags cross-host URLs and oversize files, and performs a health check on a sample. Pricing is also disclosed, which is beyond 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 a single sentence that lists all major actions efficiently. It front-loads the main purpose ('Sitemap validator') and then details behaviors. Pricing is appended in parentheses. No filler or redundancy.

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?

Given the tool has an output schema, annotations, and only one parameter, the description covers the core functionality well. It explains what the tool does, how to call it (input), and includes cost. It doesn't describe ouptut format (but output schema covers that) or limitations, but overall is sufficient for a read-only validator.

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 single parameter 'url' has schema coverage 100% with description 'Site root or direct sitemap URL'. The tool description repeats this ("?url=site root or sitemap URL") without adding new semantics. Baseline is 3 as schema covers the parameter adequately.

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 begins with 'Sitemap validator:' and enumerates specific operations: finds sitemap, handles indexes, validates entries, flags issues, health-checks URLs. The verb 'validates' and resource 'sitemap' are precise, and the tool is clearly distinguished from sibling SEO tools like get_seo_robots_check or get_seo_full_audit by its focus on sitemap content.

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 sitemap validation but does not provide explicit guidance on when to use this tool versus alternatives (e.g., get_seo_robots_check for robots.txt or get_seo_full_audit for a broader check). No when-not-to-use or alternative recommendations are given.

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