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

Annotations already establish read-only, idempotent, non-destructive behavior, and the description adds genuinely new context: seals are re-checked daily against the reference the publisher approved, and the payload differs depending on whether the caller is the owner (proof, approved and current readings, selected seals, cancellation details) or an anonymous viewer (public status only). That visibility split is the kind of behavior an agent cannot get from structured fields.

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 opening is a noun fragment rather than a verb-led statement, and the second sentence ('Public seal status for a listing') largely restates the first, so the front-loading is slightly muddled. The owner/public distinction in the final sentence does earn its place, but the middle sentence is close to filler.

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?

With no output schema, the description must convey return content, and it does: seal types, per-seal status, and the extra owner-only fields including approved vs current readings and cancellation details. What remains unstated is the shape of the response (per-seal objects vs summary string) and failure behavior for unknown or non-existent listing IDs.

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 exists and schema description coverage is 100%, with the schema itself explaining the mcp_ prefix and the /api/listings source. The description adds no further meaning about the identifier. Baseline 3 applies when the schema fully carries parameter semantics.

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 names a specific resource (verification seals of a listing) and enumerates the seal types covered: code, DNS, IP, TLS and domain. An agent knows exactly what data is returned. It does not, however, distinguish itself from adjacent siblings such as listing_security, get_listing, or listing_status, so differentiation must be inferred.

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?

There is no explicit 'use this when' statement and no named alternative. The mention that 'the owner also sees the proof' hints at a visibility distinction but never tells the agent when to prefer this tool over listing_security or get_listing, nor what prerequisite conditions (ownership) change the result.

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