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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false. The description adds meaningful context beyond that: the data is limited to what the deployment's operator credential can manage, the projectId does not affect the answer, and the tool makes live Google API calls. It stops short of disclosing pagination, rate limits, or error behavior.

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 front-loaded with the primary purpose, followed by the key scoping caveat, the exact return shape, and the live-API note. Every sentence carries distinct 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?

With only one required parameter, no output schema, and annotations covering the safety profile, the description is complete. It supplies the exact return object shape, clarifies the projectId caveat, identifies the consumer tool, and notes live API calls, leaving no critical gap for correct invocation.

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%, so the schema already documents projectId as required and sourced from list_projects. The description adds critical semantic clarification that the answer does not depend on the project passed and that projectId only satisfies an ownership check, which materially changes how an agent should interpret the parameter.

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: listing every Google Business Profile account and location manageable by the deployment's operator credential. It distinguishes this tool from set_gbp_connection by calling itself the picker data for that tool, and it clarifies that the result is not project-scoped. An agent can identify its role 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?

The phrase 'the picker data for set_gbp_connection' clearly signals when to use this tool, and the note about projectId only satisfying an ownership check prevents a common misuse. It does not explicitly compare against other GBP listing siblings such as get_gbp_profile or get_gbp_connection, so it falls just short of full alternative routing.

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