verify_domain_with_credentials

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

Annotations declare readOnlyHint=false and destructiveHint=false, so the agent knows this mutates state without destroying it. The description adds substantive context beyond that: it requires a Proof account and explains the two auth paths (set PROOF_API_KEY and restart, or sign in via start_login). This auth requirement is genuinely useful behavioral disclosure not covered by 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?

Two short paragraphs: purpose first, then an ACCESS block. Front-loaded and free of filler, though the ACCESS paragraph is somewhat verbose for a note that could be tighter. Every sentence still carries useful 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 one-parameter mutation tool with annotations and full schema coverage, the description covers purpose, precondition, and the authentication requirement, which is the main non-obvious friction. No output schema exists, so return values need not be described. Only the alternative-tool routing 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?

Schema description coverage is 100% and the single 'id' parameter is documented as 'Domain ID to verify.' The description reinforces that the domain must be 'pending' but adds no syntax, format, or lookup guidance for the id beyond the schema. Baseline 3 is appropriate.

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 (verify) and resource (pending domain) plus the distinguishing mechanism: 'using previously stored DNS credentials.' This separates it from the sibling verify_domain, which presumably relies on manual DNS records, even though the alternative is not named outright. Slightly short of 5 because the differentiation is implied rather than explicit.

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?

'Use when credentials are already connected' gives an explicit precondition that tells the agent which situation selects this tool over the credential-less verification path. It stops short of stating the when-not case (e.g., use connect_dns_provider/create_dns_credential when no credentials exist), so it lacks full alternative routing.

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