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

Adds real context beyond annotations: it names the response fields (`found`, `why`) with their possible values, discloses the up-to-an-hour DNS propagation delay, and states owner-only access. openWorldHint=true is corroborated by the description's implicit outbound lookup, and nothing contradicts the annotation set.

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?

One dense sentence starting with the action, then the result semantics, then the timing caveat and access restriction. No wasted words and the key information is front-loaded.

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?

With no output schema, the description usefully explains return values and their failure modes, plus latency and auth. It leaves out whether the check triggers outbound fetches with side effects on the target site, which matters given openWorldHint=true.

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% and the single domain_id parameter is fully documented in the schema (uuid from list_domains). The description adds no further meaning about the parameter, 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 concrete action (look for a domain's tag, DNS record or file) that is clearly the verification step for a domain, distinguishable from list_domains, add_domain and remove_domain. It doesn't explicitly frame itself as 'verify ownership', so an agent must infer the intent from the enumerated check targets.

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?

'now' and the DNS propagation caveat imply the useful moment to call it (right after a domain is configured or a record added), and 'Owner only' gives a permission prerequisite. However no alternatives or explicit when-not conditions are named, so the routing between this and sibling domain 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.