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

With no annotations, the description carries full burden. It discloses the authentication requirement and the data returned, but does not explicitly state that the operation is read-only and side-effect free. This is an implication from the verb, but not explicitly stated; the auth note is useful.

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 a single focused sentence on purpose followed by a concise authentication note. No filler; the most important information is front-loaded. Efficient and well-structured.

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 simple one-parameter getter with no output schema or annotations, the description is nearly complete. It states what is returned and how to authenticate, but does not explicitly mention it is a safe read-only call or what happens if the domain doesn't exist. Minor gaps, but largely sufficient.

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% for the single 'id' parameter, so the schema already documents it. The description only repeats that it's 'by ID' without adding extra context like where to find the ID or format constraints. Baseline 3 is appropriate.

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 clearly states the tool fetches details of a specific domain by ID, listing the returned information (verification status, DNS records, provider connections). This is a specific verb-resource combination and distinguishes it from siblings like list_domains or get_user_domain_verification_status.

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?

It implicitly indicates this is for a single known domain (by ID) and provides explicit authentication prerequisites (Proof account, authenticate via /mcp or start_login). It does not explicitly mention alternatives like list_domains for discovery, but the usage intent is clear enough.

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