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

Annotations already declare readOnly, idempotent, non-destructive behavior, so the safety profile is covered. The description adds real behavioral context beyond that: the data is 'commonly reported' (not authoritative), each row carries a source, and the response self-documents the box-printed-odds hierarchy. It stops short of noting data freshness or coverage limits.

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?

Two sentences, densely front-loaded with the verb, resource, and breakdown, followed by the ranking caveat. No filler, though the second sentence's phrasing ('and the result says so') is slightly indirect for the value it carries.

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 no nested objects, the burden of describing the return falls on the description, which does so adequately (per-row odds grouped by series format, each with a source, plus a precedence note). A brief note on coverage scope or how to resolve a specific series would make it fully complete.

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 no parameters, so there is nothing for the description to disambiguate; the baseline of 4 applies. The description appropriately spends its words on output semantics instead.

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 (commonly reported secret/chase odds for Labubu / The Monsters blind-box series) and the granularity (by series format: 6-figure, 12-figure, collabs, glow variants) plus provenance (per-row sources). It implicitly separates this lookup tool from the probabilistic siblings like secret_pull_probability, but never names an alternative, so it falls short of a 5.

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: consult this when you want reported/chase odds per series format. The caveat that box-printed odds outrank any returned row is useful prioritization guidance, but the description never states when to prefer this over sibling tools such as secret_pull_probability or calculate_style_probability.

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