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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds value beyond that: the call is free (no quota/billing cost) and requires the creation-time webhook_secret as an auth credential, which an agent must know before calling.

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 dense sentences, front-loaded with the 'Free' cost signal and the resource identity, followed by the returned fields and the auth prerequisite. Slightly list-heavy but every clause carries 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?

There is no output schema, so the description usefully enumerates what the status payload contains and flags the auth requirement and zero cost. That is enough for an agent to call it correctly, with only error/not-found behavior left unstated.

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%, with both watch_id format (ocw_ pattern) and webhook_secret provenance already documented in the schema. The description restates the webhook_secret requirement without adding syntax, format or failure-mode detail, so the schema is doing the heavy lifting.

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: retrieves status of a paid domain watch, and enumerates the fields returned (items, expiry, last check, DNS/IOC/claim state, webhook delivery). It also anchors the resource to its creation endpoint (HTTP POST /v1/watch), which clearly separates it from the check_* siblings, though no sibling is named explicitly.

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?

Makes the usage context clear: this is for a watch that already exists (created via POST /v1/watch) and requires the webhook_secret issued at creation. It does not name alternatives or state when-not-to-use, but the precondition framing leaves little ambiguity about when to reach for it.

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