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

Annotations already declare readOnlyHint and destructiveHint=false, so the lower bar applies. The description nonetheless adds real behavioral context: the status vocabulary, that 'discovered' means parsed not crawled/indexed, the 1,000-item cap, and the API-key/auth requirement.

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?

Front-loaded with the resource and returned fields, then the discovered-pages caveat and cap. Slightly long and lists status values inline, but each clause carries information; no real waste.

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 single-param read-only list tool, it covers purpose, output content, semantics, limits, and auth. It stops short of naming sibling alternatives or pagination behavior, but nothing essential is missing.

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 coverage is 100% and the schema already explains the property format (sc-domain: vs URL-prefix). The description adds no additional parameter meaning, so baseline 3 applies.

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 (list) and resource (sitemaps of a Search Console property) and enumerates the exact fields returned (sitemap URL, type, last submit, last read, status, discovered pages). An agent can distinguish this from submit_sitemap and from other GSC report tools without opening the schema.

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?

Implies usage (to see what the Sitemaps report shows) and notes the scope limitation, but never names alternatives such as submit_sitemap or list_pages_by_index_status, nor states when-not-to-use. Clear context without explicit exclusions.

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