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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the agent knows this is a safe read operation. The description adds that it lists 'submitted' sitemaps, which clarifies the scope. However, it doesn't disclose what happens if no sitemaps are submitted, whether the response includes sitemap status/details, or any rate-limit considerations. With annotations covering the safety profile, a 3 is appropriate.

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, concise sentence that front-loads the action and resource. There is zero waste, and every word earns its place. The parameter schema carries the additional context, keeping the description appropriately minimal.

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 simple read-only list tool with one parameter, the description plus schema is nearly complete. The schema covers the parameter fully, and annotations cover the safety profile. The only minor gap is that the description doesn't mention what the output looks like (e.g., list of sitemap URLs, statuses), but since there is no output schema, a bit more detail on return values could help. Still, the tool is simple enough that this is a minor 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?

Schema description coverage is 100%, so the schema already documents the single parameter (site_url) with a clear example and a pointer to list_gsc_sites. The description itself doesn't add parameter-level detail beyond what the schema provides. Baseline 3 is correct when the schema does the heavy lifting.

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 ('List') and resource ('submitted Google Search Console sitemaps') for a connected property. It is clear about what the tool does, though it doesn't explicitly distinguish itself from sibling tools like list_gsc_sites or query_gsc_search_analytics. The title and description align well.

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 context: it is for listing sitemaps for a connected property. The parameter description for site_url explicitly says 'Use list_gsc_sites to choose an available property,' which provides a clear pointer to a sibling tool for selecting the property. However, it doesn't explicitly state when not to use this tool or mention alternatives for other sitemap-related operations.

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