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

Annotations already flag destructiveHint=true and openWorldHint=true, and the description goes well beyond them: it discloses idempotent replacement semantics ('a new address replaces the old one, the same address again changes nothing'), the host-validation constraint, that the call is free, the required 'act' scope, and the shape of the response. This is exactly the mutation and side-effect context an agent needs before calling a destructive write.

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?

Front-loaded with purpose, then clearly partitioned by 'WHEN' and 'WHAT COMES BACK' labels, with no filler. The telegraphic phrasing ('handed you the move it belongs to') is slightly compressed, but every clause carries information.

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 two-parameter write with no output schema, the definition covers cost, auth scope, uniqueness, replacement behavior, validation, and return contents, so nothing an agent needs in order to call it correctly is missing.

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 both parameters are already documented, but the description still adds real meaning: 'one address per site' explains the uniqueness relationship between surface and url, and 'the address must sit on that site's own host' is a validation rule absent from the schema.

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?

States a specific verb and resource ('File one public profile or listing') plus the scope ('on a directory site') and the downstream effect ('counts it as a verified presence'). An agent can distinguish this from record_claim or record_content 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?

The 'WHEN' clause gives explicit preconditions: the profile must be the user's, and the user must have asked for it to be filed or handed over the associated move. It stops short of naming an alternative sibling (e.g. record_claim) for the case where the presence is not yet live, so the routing guidance is clear but not exhaustive.

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