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

Annotations already declare readOnlyHint=true and openWorldHint=false, and the description is consistent with them rather than repeating them. It adds genuinely new behavioral context: the OAuth scope required and what comes back (status plus DNS instructions and validity timestamps when present). It does not cover error behavior or what an unverified state returns.

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 sentences, each earning its place: purpose, auth prerequisite, return contract, and a non-mutation disclaimer. The core purpose is front-loaded in the first clause with no preamble.

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 read tool with no output schema, the description supplies the missing pieces: the OAuth scope needed to call it, the shape of the returned data, and confirmation that nothing is mutated. An agent has everything required to decide and invoke correctly.

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 (secret, clientId) are documented in-schema, including the Bearer header alternative. The description adds nothing about parameter form or precedence, which is acceptable given the schema does the heavy lifting, so the baseline 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?

States a specific verb and resource ('Read DNS domain-control verification') scoped to 'your currently authenticated agent', which is far more precise than a bare name restatement. It stops short of naming the sibling alternatives (kya_challenge, kya_verify) explicitly, so the contrast with them must be inferred from the resource name.

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?

Gives a clear precondition ('Needs commerce.read for OAuth') and a negative boundary ('does not change the contact, challenge or verification'), which tells the agent this is not the tool for mutating verification state. It never names which sibling to use instead when the agent wants to trigger a challenge or verify, so routing is only implied.

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