search_acme_certificate_domains

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

Annotations already declare readOnlyHint=true and destructiveHint=false. The description adds valuable behavioral context beyond annotations by explaining that the tool fetches the parent certificate rather than querying a standalone list endpoint, which clarifies the underlying mechanism and reinforces the read-only nature.

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?

The description is two sentences with no fluff. The first sentence states the core purpose, and the second provides necessary implementation context. Every word earns its place.

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?

Given the tool's simplicity (read-only, two parameters, output schema present, annotations cover safety), the description is highly complete. It explains the API quirk and method, while return values are covered by the output schema. No critical information 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?

The input schema already documents both parameters with 100% coverage. The description adds meaning by explaining why parent_id is required ('fetches the parent certificate'), which goes beyond the schema's simple 'ACME certificate ID' description. It does not add detail for search_term, but that is adequately covered by the schema.

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 states a specific action ('List the domain (SAN) validation entries') on a specific resource ('an ACME certificate'). It clearly distinguishes this tool from siblings like search_acme_certificates (which lists certificates) and manage_acme_certificate_domain (which manages domains) by focusing on read-only retrieval of domain entries.

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?

The description explains that the API embeds domain lists inline on the certificate object and that this tool fetches the parent certificate, providing clear context for when to use it. It implies the need to first obtain parent_id via search_acme_certificates, though it does not explicitly name an alternative tool or state when not to use it.

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