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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=true, and destructiveHint=false, so the safety profile is covered. The description adds useful context that the results are limited to 'verified' sites and that the tool is a discovery step, but it does not add behavioral details such as return format or pagination. With rich annotations, this is adequate but not exceptional.

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 two sentences with no filler. The core action and scope are front-loaded, and the usage guidance earns its place by explaining when the tool should be invoked.

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 one-parameter, read-only list tool with strong annotations and full schema coverage, the description is nearly complete. It explains purpose, scope, and sequencing. It does not describe the output shape, but for a list operation the return type is largely inferable, and the missing detail is minor.

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%, and the companyId parameter is fully documented in the input schema. The description adds no parameter-level meaning beyond what the schema already provides, so the baseline score of 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?

The description states a specific verb ('List'), a clear resource ('verified sites/properties in Google Search Console'), and an explicit scope ('all'). It also gives the operational context of discovering available sites before querying search performance, which distinguishes it from related siblings like get_search_performance or get_sitemaps.

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 explicitly says to use this tool first to discover available sites before querying search performance, providing a clear situational trigger. It does not explicitly state when not to use it or name a precise alternative tool, but the guidance is specific enough to route an agent correctly.

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