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

No annotations are provided, so the description carries the full disclosure burden, and it does not mention that this call creates a pending verification state on the account, what happens on repeated calls, whether the issued record expires, or what permissions are required. It reads like a benign read ("Get a TXT record") while the tool actually initiates a verification process — without annotations there is nothing to correct that impression. Idempotency is handled only in the schema, not in the description.

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 sentences with zero waste: the deliverable and its placement constraint first, the required follow-up call second. Nothing is buried and nothing is repeated.

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?

There is no output schema and no annotations, so the description should say more about what comes back beyond "a TXT record" (host/name label, expected value, TTL) and how the agent should report success or failure. It is adequate for a 2-parameter tool and correctly delegates the next step, but for a state-changing verification flow with no structured metadata it leaves real gaps.

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 50%: idempotency_key documents itself fully, while domain is a bare string in the schema. The description compensates by specifying that domain must be the account email domain or a parent domain, which is genuine semantic value the schema does not provide. Remaining minor gap is that it doesn't clarify formatting (bare domain vs URL) for the domain value.

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 names the concrete artifact produced (a TXT record) and the domain scope it must belong to, so the agent knows this kicks off DNS-based verification. It also distinguishes itself from the follow-up sibling check_dns_verification. It stops short of stating the action in its own terms (initiate verification) and never contrasts with start_email_verification, but the resource is unambiguous.

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?

"Then call check_dns_verification" explicitly sequences the next step, which is the single most important routing hint for this tool. The parenthetical "(or a parent domain)" tells the agent what input is acceptable. What's missing is when NOT to use this path — with start_email_verification as a sibling, the agent gets no rule for choosing between the email and DNS verification flows.

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