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

Annotations already establish it as read-only, idempotent, non-destructive, and closed-world. The description adds value by disclosing that the signals are compiled, not a guarantee, that limitations are included, and that each check has named public sources—provenance and reliability context not captured by annotations.

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, front-loaded with the core content and followed by a concise caveat. The parenthetical list of eight checks is dense but earns its place by specifying exactly what the tool returns.

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?

For a no-input read-only resource with rich annotations and no output schema, the description covers the core content (eight checks, sources, limitations). It could specify the return format or that it is static, but given the lack of an output schema, it is nearly 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 zero parameters, so there are no parameter semantics to document. Per the baseline, a 0-param tool earns 4; the empty schema with additionalProperties false is self-evident and needs no description.

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?

Names the specific resource (eight authenticity checks for a Labubu figure) and enumerates them, making it distinguishable from siblings like style probability or rarity odds. However, it uses a noun phrase rather than an action verb (e.g., 'Get...'), so it is slightly less direct than 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?

Provides no explicit when-to-use, when-not-to-use, or sibling alternative. The caveat 'not a guarantee' is a limitation, not guidance for selecting this tool over define_labubu_term or get_collecting_guide.

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