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

The annotations already declare readOnlyHint=true, so the safe-read behavior is covered. The description adds useful detail about what is returned and why pack ids matter, but it does not disclose behaviors like ordering, pagination, or localization defaults beyond what the schema already provides.

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. The core action and output fields are front-loaded, and the clarifying statement about pack ids earns its place by adding practical use context.

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 read-only list tool with zero required parameters and a fully documented schema, the description is complete. It states what will be listed, the fields returned, and why the result matters. No output schema exists, but the description sufficiently covers the return value shape.

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?

Parameter schema coverage is 100%: the only parameter, locale, is already described with its default value. The description's mention of 'localized name' aligns with the locale parameter but adds no new semantic detail beyond what the input schema provides, so the baseline of 3 applies.

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 uses a specific verb ('List'), a clear resource ('every Pokémon TCG Pocket booster pack'), and names the exact fields returned (id, parent set id, localized name). It also clarifies the distinction between packs and printings with 'Pack ids identify where a printing can be pulled,' which helps separate it from siblings like list_sets and list_printings.

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 makes the tool's scope unambiguous: list every pack, with no filtering. The closing sentence gives practical context for when a pack id is needed. It does not explicitly name alternative tools or state when not to use it, but the context is clear enough for an agent to select it correctly.

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