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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds genuine value beyond that by disclosing the return contents (date, precision, recall per proof) and the strict filtering rule that only proven signals appear. It does not mention ordering, size limits, or whether results can change over time, which is a minor gap.

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?

Three short sentences, front-loaded with what is returned and its fields, then the sibling pointer, then the exclusion. Every sentence carries distinct information with no repetition of the tool name or title.

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 parameters, no output schema and annotations covering the safety profile, the description supplies the remaining essentials: what each record contains and what is deliberately omitted. Nothing an agent needs in order to call this correctly 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 takes zero parameters, so the baseline is 4. There is nothing for the description to disambiguate, and it correctly does not invent any input guidance.

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 states clearly that this returns signals proven against a live public source, along with proof date, precision and recall, and explicitly excludes pending or planned items. The verb is implied rather than stated (it reads as a noun phrase, 'The signals ... has proven'), and the term 'shinnslist' is an unexplained proper noun, so an agent gets the resource and scope but must infer the list action from the tool name.

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 names the sibling that takes over the next step ('run one with run_signal'), which is a concrete when-to-use-this-vs-alternative pointer. It also carves out what is not here ('Nothing pending or planned appears here'), but gives no guidance about the other siblings (check_parcel, find_parcels, list_coverage) that an agent might confuse with this one.

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