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

The annotation readOnlyHint=true already establishes that this is a safe read operation. The description adds the 'poll' behavior and the possible states, but does not disclose additional details like polling intervals or error behavior. Given the annotation coverage, the description adds modest value, hence a 3.

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 a single, front-loaded sentence that immediately communicates the purpose and usage. Every word earns its place, and there is no redundancy or 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 simple polling tool with one parameter and no output schema, the description covers the essential context: when to use it, what it returns, and the states. It does not specify error handling or timeout behavior, but these are not critical for an agent to invoke it correctly. Slight gap, hence 4.

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?

With 0% schema description coverage, the description must clarify parameter meaning. It does mention 'for an email', which identifies the sole parameter's role, but does not elaborate on format or constraints. This is minimal but sufficient for a single string parameter, so a 3.

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 action (poll) on a specific resource (onboarding state for an email) and lists the possible return values. This clearly distinguishes it from generic status tools like get_status and aligns with the account lifecycle tools (create_account, delete_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 explicitly states when to use it: 'Use after create_account while waiting for the human to verify.' This provides clear context for the typical workflow, though it does not mention alternatives or when not to use it. Since the context is sufficient for an agent to decide, a 4 is appropriate.

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