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

Annotations already declare readOnly/idempotent/openWorld/non-destructive, and the description adds real context beyond them: it is free, rate-limited, and returns only 'safe signals and issues' rather than the paid evidence bundle or attestation. This sets expectations about output scope and throttling that the annotations do not convey.

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?

A single dense sentence with the free/rate-limited/free-tier framing front-loaded before the scope and the paid contrast. No 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 an output schema handling return values and annotations covering the safety profile, the description supplies the remaining essentials: cost tier, rate limiting, and free-vs-paid output scope. Only the explicit alternative tool choice is left implicit.

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%, so both parameters are already documented. The description reinforces that only one public endpoint per call is previewed and that it must be public, but adds no format or identifier semantics beyond the schema baseline.

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+resource: a live trust preview for one public endpoint, and immediately contrasts it with the paid trust scan that adds evidence/attestation. An agent can tell what it gets without opening the schema, though no sibling tool is named directly.

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?

'Free live, rate-limited' and 'for one public endpoint' give clear selection context, and the mention of the paid trust scan that 'adds them' signals the upgrade path. It stops short of an explicit 'use this when X, use the paid/other tool when Y' statement.

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