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

Annotations already cover safety (readOnlyHint=true, openWorldHint=true), so the description only needs to add context, and it does: it discloses exactly which statistics are returned (frequency of underperformance vs Bitcoin and average move) and the specific window (the week before the unlock). It stops short of noting data-source caveats or coverage limits, which keeps it from a 5.

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 sentence that front-loads the rating explanation and then the track record, with no filler or repeated phrasing. Every clause carries distinct information.

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 and no output schema, the description bears the burden of telling the agent what comes back, and it does so at a conceptual level (per-strength buckets, pre-unlock week, hit rate and average move). The exact shape of the response is left unspecified, which is a minor gap for a reference tool.

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 and there is nothing for the description to compensate for. The empty schema is consistent with a fixed reference lookup.

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 gives a specific verb-and-resource pair: it explains the strong/medium/small rating scheme and supplies historical statistics on past unlocks. It implicitly separates itself from the sibling unlock-listing tools by framing the output as methodology plus aggregate track record rather than individual unlock events, though it never names those siblings.

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?

Usage is implied rather than stated — an agent can infer this is the reference tool you consult to interpret a rating returned elsewhere. There is no explicit 'use this when…' or 'do not use for individual unlock dates, call get_upcoming_unlocks instead' routing.

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