gsc_list_sites

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

The readOnlyHint annotation already establishes safety, and the description adds useful context by showing the return shape, permissionLevel values, and the requirement that URL Inspection needs siteFullUser or siteOwner. It does not cover edge cases like empty results or errors, but for a read-only listing tool the disclosed behavior is solid.

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 compact and front-loaded: purpose, return format, permissionLevel enum, and usage ordering are each conveyed in a few short sentences. Every sentence adds information and there is no filler.

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 zero-parameter, read-only listing tool, the description is complete. It explains what is returned, what the permissionLevel values mean, and how this tool relates to the follow-up URL Inspection workflow. The presence of the output schema further reduces the need to document return values.

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 tool has zero parameters, so there is nothing for the description to clarify. The baseline of 4 applies because the schema is already complete and the description correctly focuses on the output rather than parameter details.

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 and resource: 'List every verified Search Console property accessible to this service account.' This clearly distinguishes gsc_list_sites from siblings like gsc_list_sitemaps, which list a different resource type. The scope is also explicit: accessible properties for the service account.

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 gives explicit ordering guidance with 'Call this first' and explains why permission levels matter for URL Inspection. It does not explicitly mention when not to use this tool or name an alternative, so it stops short of a full 5.

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