Sites and domains verified

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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, destructiveHint false, openWorldHint), so the bar is lower. The description still adds real context beyond them: the result set spans all Google products rather than only Search Console, which is a scope trait an agent would otherwise not know.

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?

Three short sentences with purpose front-loaded. Sentences two and three slightly overlap in motivating the tool's distinctness, but nothing is padding or restated boilerplate.

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-required-parameter read tool with annotations and no output schema, the description covers purpose, scope breadth, and the sibling decision. The only gap is that it doesn't hint at the shape of the returned entries (e.g., domain vs product fields), which is minor given the absence of an output schema.

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 single 'account' parameter is fully documented in the schema, including the guidance to call list_accounts. The description adds no parameter detail of its own, so the 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?

Names a specific resource (every site and domain the signed-in Google account has verified ownership of) and its broadening scope across all Google products. It explicitly distinguishes itself from the sibling list_sites, so an agent can route between them without opening either 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?

States the exact condition that selects this tool ('tell "not verified yet" apart from "verified but never added"') and names the narrower alternative (list_sites) with the reason a verified domain may not be a Search Console property. When-to-use and sibling routing are both explicit.

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