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

With no annotations, the description carries the burden, and it discloses the access requirement, the need to authenticate, and the call-after-session behavior. It also states the returned content (metadata, credential fields, docs links), making the read-only nature clear for a getter with no side-effect warnings.

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 purpose is front-loaded in the first sentence, and the access note is a compact second paragraph with no filler. The structure makes the primary action and prerequisite immediately visible.

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 zero-parameter metadata getter with no output schema, the description covers what it returns, the account requirement, and the exact authentication path. Nothing essential 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 tool has zero parameters and 100% schema coverage, so there is nothing for the description to add. The phrase 'all supported DNS providers' usefully confirms the unparameterized, unfiltered scope.

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 and resource: 'Get metadata for all supported DNS providers,' and specifies the content (required credential fields, documentation links). This differentiates it from sibling tools like list_dns_credentials, which would cover user-created DNS credentials rather than the catalog of supported providers.

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?

Provides clear context: a Proof account is required and explains the authentication flow via /mcp authenticate or start_login before calling the tool. It does not explicitly name alternatives or exclusions, but the prerequisite instructions are enough for correct use.

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