List the closed vocabularies

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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior, so the description does not need to repeat those. It adds valuable behavioral context by explaining that the strings are exact and that 'Rare Rainbow' and 'Rainbow Rare' are different, implying the tool returns canonical strings with no fuzzy matching. This goes beyond the 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?

The description is two sentences with no filler. It leads with the core purpose, then gives a practical usage note. Every sentence earns its place, and the example is concrete without being verbose.

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 simple one-parameter tool with no output schema, the description covers what it does, when to use it, and why exactness matters. It does not explicitly state the return format (e.g., a list of strings), but that is strongly implied by 'The exact strings the catalogue uses'. Given the low complexity and annotations covering safety, this is sufficient.

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 description coverage is 0%, so the description must explain the parameter. It does so by listing the vocabulary categories (types, supertypes, subtypes, rarities) that map directly to the enum values. It clarifies that the tool returns the exact strings for the chosen vocabulary, adding meaning beyond the raw enum names.

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 the tool returns the exact strings the catalogue uses for types, supertypes, subtypes and rarities, which is a specific verb+resource. The title 'List the closed vocabularies' reinforces this. It is clearly distinct from siblings like ptcg_search_cards or ptcg_list_sets, as it focuses on vocabulary reference data.

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?

The description gives explicit guidance: 'Call this before filtering on a rarity or a type rather than guessing the wording'. This tells the agent when to use it and why, using a concrete example of string mismatch. While it does not name alternative tools, the scenario is specific enough to avoid confusion with search or listing tools.

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