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

Annotations already mark the operation read-only, idempotent, and non-destructive; the description adds meaningful behavioral detail by disclosing that dormant priced doors answer HTTP 402 with empty accepts[] until a payment rail is live and that honesty grades flag weak measurements. No contradiction with annotations exists.

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 longer than average but information-dense: it covers scope, trust-block contents, dormant-door behavior, and filtering options. It is front-loaded with the registry purpose and contains no filler or redundant restatement of the tool name.

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 read-only registry with two optional parameters and no output schema, the description compensates well by explaining the returned trust fields, endpoint categories, honesty-grade caveat, and dormant-door HTTP behavior. It is not fully complete because the exact response shape and the meaning of 'one field across every zone' are left unspecified, but the practical call context is well covered.

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?

Both parameters are fully documented in the schema: zone as a hostname or fragment, and trust_only as a boolean. Because schema coverage is 100%, the description carries little additional semantic burden. The phrase 'ask for one field across every zone' is vague and not clearly mapped to trust_only, limiting added value over 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 clearly identifies list_doors as the registry of every machine-callable door and enumerates the trust-block fields returned: source, validation method, check date, and honesty grade. This distinguishes it from domain-specific siblings like nyc_ticket or popla_outcomes, though it never names a sibling 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?

The description advises agents to read the trust block before believing a tool result, giving a clear when-to-use context. It also provides concrete invocation options: filter by zone or request data across every zone. It does not explicitly list exclusions or alternative tools, but the registry role makes the use case reasonably self-evident.

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