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

Annotations already mark the tool as idempotent, non-destructive, and not read-only, and the description adds important behavioral nuance: it marks verified on success, distinguishes 'not published yet' from 'wrong value' from 'incomplete lookup', and states incomplete lookups are transient, not DNS verdicts. It also discloses that the tool never applies DNS changes itself and that a human publishes records, which is valuable beyond the annotations.

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 description is longer than average, but every sentence earns its place: purpose, outcome disambiguation, success side effect, exact-print instruction, and human-DNS safety caveat. It is front-loaded with the core action and structured so operational cautions follow the primary behavior without burying it.

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 single-parameter tool with an output schema, the description covers the essential runtime behavior: what triggers verification, how to interpret ambiguous results, what success carries, and what the agent must not do. Combined with the rich input schema and annotations, nothing an agent needs 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?

The input schema already provides 100% coverage for the only parameter, domain, and that schema description is unusually detailed about eligibility and refusal behavior. The tool description adds essentially only the phrase 'domain the user has added,' which adds little beyond the schema. Baseline 3 is appropriate when the schema carries the semantic weight.

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 opens with a specific verb and resource: check whether the ownership TXT record for a domain the user has added is visible yet, and mark it verified when it is. This clearly distinguishes the tool from generic record checks and states the mutating verification outcome. It also explains the result disambiguates failure modes, reinforcing the tool's exact purpose.

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 operational context: this is for verifying an added domain's ownership TXT record. The input schema reinforces when it is permitted by requiring the domain to already be monitored and explicitly refusing other names as not found. It does not explicitly compare against sibling tools like check_propagation or check_record, so it stops short of a 5.

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