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

With no annotations provided, the description must carry the full burden of behavioral disclosure. It clearly states the tool mutates state (resets stamp count, increments counter), which is good. However, it doesn't mention potential failure cases (e.g., if the card hasn't reached required stamps, what happens?), or any authentication/permission requirements, given the tool takes a 'token' parameter. It also doesn't describe return value or side effects beyond the two mentioned.

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 one elegant sentence that front-loads the core purpose and then succinctly states the side effects. Every phrase is necessary; there is no padding. It is concise yet informative, achieving good structure.

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 the tool has no annotations, no parameter descriptions, and no output schema, the description must provide enough context for an agent to invoke it correctly. It fails to explain the meaning of 'code' and 'token', the required combination of both, and the success/failure behavior. The condition 'has reached its required stamps' is helpful, but an agent doesn't know how to check that or what happens if it's not met. This is incomplete for a mutating 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 0%, and the description provides no information about the parameters 'code' and 'token'. The description mentions 'card' but doesn't map it to 'code', nor does it explain 'token'. Since the schema only provides types (string), the agent is left guessing what these parameters mean. This is a significant gap.

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 action (redeem) and the resource (a card that has reached its required stamps), with a specific condition (has reached its required stamps). It also describes what happens (resets stamp count, increments rewards-earned counter), which helps distinguish it from sibling 'stamp' which adds stamps. However, it doesn't explicitly name a sibling to contrast with, so it's not 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?

The description implies usage context: use this tool when a card has reached its required stamps. It does not explicitly state when not to use it or mention alternatives, but the condition 'has reached its required stamps' provides a clear trigger. It doesn't compare with 'stamp' or 'get_card', leaving some ambiguity for agents deciding between tools.

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