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

The description discloses important behavior beyond the annotations: activation requires DNS proof, partial proof would authorize checks on an unproven host, and success opts the target in and permits passive checks. This is meaningful context that annotations alone do not provide.

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 first sentence is front-loaded with the core action and method. The additional sentences earn their place by explaining the proof requirement, the risk of partial activation, and the success state, though some wording is more philosophical than strictly necessary.

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 one-parameter tool with no output schema, the description covers the key operational details: what must be true before calling, what happens on success, and why the proof rule exists. It does not describe failure behavior or return values, but those are less critical given the clear postcondition.

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 covers the only parameter fully, including its source ('as returned by propose_target'). The description does not add further parameter-level detail, but the baseline of 3 is appropriate because the schema already provides sufficient meaning.

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 verb ('activate'), the resource ('a target you control'), and the required proof method ('by DNS TXT record'). It clearly distinguishes this from sibling tools by framing it as an ownership-proof activation step rather than a claim or proposal.

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 gives a clear precondition: every declared domain must carry the TXT record before activation. It also explains the consequence of partial proof, which implicitly tells the agent when not to call it. However, it does not explicitly name alternative tools or contrast them.

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