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

The readOnlyHint annotation already signals a safe read, and the description adds meaningful behavioral context: Trainer cards return rules text and subtype instead of attacks, and both printing and gameplay card IDs are accepted. This goes beyond the annotation without contradicting it.

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 sentences, front-loaded with the core purpose and field list; each sentence earns its place: data content, the Trainer exception, and accepted ID formats. No filler or redundant restatement.

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 output schema, the description enumerates the returned card attributes and calls out the Trainer-card variation, giving an agent a solid picture of what to expect. Minor gaps like invalid-ID behavior are acceptable for a read-only lookup 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?

Schema description coverage is 100%, and the schema already documents both parameters with the same ID examples and locale default. The description reinforces the ID forms but does not add new parameter-level meaning, so the baseline of 3 is appropriate.

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?

States a specific action ('Get') and a specific resource ('one Pokémon TCG Pocket card's available catalog data') with an enumerated field list. The singular-card scope clearly distinguishes it from list/search siblings, and the two accepted ID formats are explicitly given.

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 implies the usage case—fetch card data when you already have an ID—by spelling out both accepted ID formats. However, it offers no explicit when-not guidance or pointer to search_cards/list_printings for lookup without an ID, so routing guidance is mostly implicit.

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