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

Annotations cover the safety profile (readOnly=false, openWorld=true, destructive=false, idempotent=false). The description adds genuinely useful non-structured context: the tool triggers an outbound action by Google (postcard/call/SMS/email) and does NOT complete verification, plus an explicit user-confirmation prerequisite. It omits the mismatch between the offered idempotencyKey and idempotentHint=false.

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 tight sentences with the core action front-loaded, then the downstream behavior, then the pre-call prerequisite. No filler or restatement of the name.

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 no output schema, the description correctly explains what actually happens as a result (Google dispatches the code; the owner finishes elsewhere). It does not say what this call returns (e.g., a pending-verification record), which is the only notable gap for a 6-parameter side-effecting tool.

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%, so all six parameters are already documented in the schema, including the method sourcing from list_gbp_verification_options. The description reinforces the method and contact-detail requirements but adds little syntax or format detail beyond the schema, 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?

Specific verb + resource: 'Ask Google to send a verification code.' It also distinguishes itself from the list_gbp_verification_options sibling (the source of allowed methods) and from the actual verification flow by stating the code is entered in Google Business Profile, not here.

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?

Clear context for use: pick a method from list_gbp_verification_options and confirm method plus contact details with the user before calling. It names the prerequisite sibling but does not mention when not to use it (e.g., when a request is already pending — get_gbp_verification_status exists as a sibling).

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