get_card_performance

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

With no annotations, the description carries the full burden. It discloses default behavior (best, top 10) and authentication requirements (IWMM_API_KEY). However, it does not explain error handling (e.g., insufficient permissions) or side effects. The absence of annotation contradiction is noted.

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, front-loaded with the core purpose, and includes essential gating information. Every part serves a clear function without redundancy.

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?

Given no output schema, the description could be more complete by detailing return fields or examples. It covers the input behavior and authentication but lacks output context. For a simple tool, it is adequate but not exhaustive.

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 compensate. It implies default values for 'type' (best) and 'limit' (10) but does not elaborate on the exact meaning of 'P&L' or how the 'worst' mode behaves. The enum and range are clear from the schema, but the description adds minimal extra value.

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 clearly states the tool retrieves the user's best- or worst-performing cards by P&L, with defaults (best, top 10). This sets it apart from sibling tools like get_card (single card info) and get_card_prices (price history), making its purpose distinct and unambiguous.

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 mentions 'Premium-gated. Requires IWMM_API_KEY,' which indicates prerequisites but does not specify when to use this tool over alternatives or what to do if not premium. No explicit when-not-to-use guidance is provided, limiting its decision support.

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