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

Annotations already cover safety with readOnlyHint, idempotentHint, and destructiveHint. The description adds useful behavioral context by specifying that the tool requires a set id from list_sets and returns both raw and PSA 10 USD prices per card, which goes beyond the structured 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?

Three sentences with no filler: use case, prerequisite, output summary, and routing rule. The primary guidance is front-loaded and every sentence earns its place.

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?

The description covers when to use the tool, the prerequisite set id, the output content, and the main alternative. Given the annotations and output schema, an agent has enough context to select and invoke this tool correctly.

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 schema documents set_id and sort, and the description reinforces set_id provenance and clarifies sort semantics via 'most valuable' and 'checklist order'. It does not add detail for game or limit, but those are reasonably self-explanatory enums and range constraints, and schema coverage is 50%.

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 a specific use case: retrieving the most valuable cards in a specific set or a priced checklist of a set. It names the resource and explicitly distinguishes itself from search_cards for single-card queries, making its purpose clear and separable from siblings.

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?

It gives an explicit trigger condition ('when the user wants the most valuable cards in a specific set or a priced checklist'), a required prerequisite ('Requires a set id from list_sets'), and a clear when-not-to-use rule with an alternative ('Do not use for a single named card; use search_cards instead').

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