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

The annotations already establish a safe, read-only, idempotent operation. The description adds useful behavioral context beyond them: pricing is in EUR, includes source and reliability, reports 7/30/90-day changes, and costs 1 credit with +1 per include.

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?

Two tightly written sentences front-load the core purpose and then add cost and contents. There is no filler or 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?

With only three fully documented parameters and no output schema, the description supplies the essential return-value context and credit cost. It could be stronger by clarifying sibling alternatives, but it is otherwise complete for this tool's complexity.

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%, so the schema already explains card_id, sealed_id, and include. The description adds the credit implication of including extras, but otherwise does not add much parameter meaning beyond the schema.

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 resource (price summary) and scope (a card or sealed product in EUR), including the returned fields: source, reliability, and 7/30/90-day changes. It does not explicitly differentiate itself from close siblings such as get_card_prices or get_price_history, which keeps it from a 5.

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?

Usage is implied by the card-or-sealed scope and the returned summary fields, but there is no explicit guidance on when to choose this over compare_prices, get_card_prices, or get_price_history. The agent must infer the appropriate situation from the description alone.

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