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

Annotations already carry the safety profile (destructiveHint=false, openWorldHint=true, readOnlyHint=false), so the description mainly needs to explain the quirks. It adds that the check is re-run ('again'), which hints at a live DNS lookup, but it does not explain why this is not read-only, whether results are cached, or how propagation timing affects results. The description of returned fields (status, missing records) largely restates what the output schema already provides.

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 sentences, front-loaded with the usage trigger and followed by the behavior. No filler; only mild redundancy in restating the return fields that the output schema already encodes.

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?

An output schema exists, so the tool needn't spell out return structure, and annotations cover safety. Remaining gaps are the undocumented site_id and the absence of any note on DNS propagation delays, which is the main source of misuse for a re-check tool.

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 only 50%: 'domain' is documented in the schema ('leave out to check them all'), but 'site_id' has no schema description and is never mentioned in the description. The phrase 'the site's custom domains' implies site scoping but doesn't define what site_id is or where the agent gets it.

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?

Names a specific action and resource: re-checking a site's custom domains and returning each one's status plus the records still missing. The trigger phrase ('user has set their DNS records') also separates it in practice from connect-domain, but the description never names that sibling, so the differentiation is inferred rather than stated.

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?

Gives an explicit when-to-use condition: after the user sets DNS records, or when they ask whether the domain works yet. It stops short of when-not-to-use guidance (e.g. don't re-check repeatedly while propagation is pending) and does not name alternative tools.

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