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

Annotations already declare idempotentHint=true, destructiveHint=false, and (notably) readOnlyHint=false, so the safety profile is supplied. The description adds that the operation inspects DNS, certificate, and liveness, and 'now' implies a freshly triggered live probe rather than a cached read - context that helps explain why readOnlyHint is false. It does not disclose latency, rate limits, or what happens if the domain is misconfigured.

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?

A single front-loaded sentence with zero filler: verb, resource, and the three things inspected. Nothing is redundant with the title or schema.

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 check tool with annotations and no output schema, the description covers purpose and the substance of the result (DNS, certificate, live status), which is enough for an agent to call it correctly. It stops short of describing the result shape or error behavior on failure, which is a minor gap given there is no output schema.

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?

Only one parameter and schema coverage is 100%; the schema itself documents that domainId comes from list_help_center_domains. The description adds no syntax, format, or ID-sourcing detail beyond the schema, so the baseline 3 applies.

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?

Specific verb ('check') plus specific resource ('a custom help center domain'), and it enumerates what is inspected: DNS records, certificate, and live status. It is distinguishable from check_mail_domain/verify_mail_domain by resource, though it never names those siblings 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?

Usage is only implied: the word 'now' suggests an on-demand re-check of a domain that has already been added (via add_help_center_domain) or is being troubleshot. There is no explicit when-to-use statement, no prerequisite, and no mention of alternative tools like list_help_center_domains or the mail-domain equivalents.

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