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

It adds behavior beyond the annotations: the tool needs profile:write, the first call is a no-op validation, unknown fields are refused by name, and the second call requires the confirm_token. The annotations already cover destructive, idempotent, and read-only hints, so this is strong supplementary context.

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?

Four short sentences, front-loaded with the action, permission, and two-step flow. Each sentence adds operational detail without 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 destructive two-phase tool with no output schema and 50% schema description coverage, the description covers the permission, validation phase, confirmation handoff, and first-call return values of summary and confirm_token. It does not describe what the second call returns on success and does not reference the related check_handle tool, so it is not fully complete.

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?

The schema already documents confirm_token's first-call and second-call use, and the description mostly elaborates that flow. The required handle parameter has an empty schema and the description only implies it is the new handle value, without format or constraints; the unknown-field validation note is useful but one parameter remains thin.

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 names a specific action and resource: changing the caller's handle. It does not distinguish this tool from related siblings such as check_handle for availability or update_profile for broader profile edits, so sibling routing relies mainly on the name and title.

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?

It gives a clear two-call protocol: call once to validate and get a summary and confirm_token, show the summary to the person, then call again only after they agree. It does not mention alternative sibling tools such as check_handle or update_profile.

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