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

Beyond the annotations (readOnlyHint=false, destructiveHint=false, openWorldHint=true), it adds the cost profile ('Free'), describes exactly what the call produces (a meta tag or DNS TXT record), and names the required next step. It does not say whether repeated calls create duplicate pending claims or how long the token stays valid, which matters for a non-read-only operation.

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 short sentences, front-loaded with cost then action then next step; nothing is filler. The opening 'Free.' fragment is slightly abrupt but carries real decision-relevant 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 state-changing tool with no output schema, the description covers what is returned (a DNS/meta verification artifact) and the required follow-up call, which is the essential loop. Gaps around token lifetime and re-invocation behavior keep it short of 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?

Schema description coverage is 100%, and both parameters (`tool` slug from find_tool, `api_key` fallback for the Authorization header) are already documented in the schema. The description adds no format or constraint detail beyond that, so the baseline of 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?

The description makes clear that the tool initiates a domain-ownership claim by issuing a verification token (meta tag or DNS TXT record), and it names verify_claim as the follow-up, so an agent can separate it from verify_claim and start_signup. It never literally states the verb 'start a claim' on the listing identified by the `tool` parameter, so the action is inferred from the title rather than the prose.

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 explicit sequencing guidance ('Add it, then call verify_claim'), which is the primary when-to-use signal. It does not contrast with start_signup (new listing) or say what to do if a claim is already pending, so the choice among sibling tools is only implied.

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