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

The description is otherwise rich — it discloses the return artifact (a publishable file or a DNS TXT record), the practical deployment path, and the unlocking effect on scan coverage. However, 'Calling it again returns the same token, so a record already published stays valid' describes idempotent repeat behavior, which conflicts with the idempotentHint=false annotation; an agent may reasonably be misled about repeat-call semantics.

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 tight sentences, front-loaded with purpose then the concrete return artifact and the next step. No filler, and every clause carries actionable 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 single-parameter tool with no output schema, the description covers what is produced (file vs DNS TXT record), how it is used operationally, what it unlocks, and the required follow-up call. Nothing an agent needs to invoke it correctly is absent.

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?

There is only one parameter and schema description coverage is 100%, so the schema already documents the domain format with examples. The description adds no additional syntax or constraint detail beyond what the schema provides, which matches the baseline for fully-covered schemas.

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+resource ('Begin proving the user owns a domain') and immediately names the payoff ('unlocks active tests (injection, XSS, SSRF, access control) on its scans'). It is clearly separable from the sibling check_domain_verification, which is positioned as the follow-up step.

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 ('Then call check_domain_verification') and explains repeat-call behavior ('Calling it again returns the same token'), which is exactly the context an agent needs before invoking it twice. It stops short of stating when NOT to use it (e.g. for already-verified domains, where list_verified_domains would answer instead).

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