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

No annotations are provided, so the description carries full responsibility. It discloses the one-way nature of the redeem parameter ('one-way'), the requirement for admin_key, and the return information (who earned it, reward, when, redeemed status). No contradictions.

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 a single, dense sentence that efficiently conveys purpose, usage, and key details. It is front-loaded with the operator context. Could be slightly more structured, but remains concise and clear.

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?

Despite no output schema, the description fully covers expected return data (who, reward, when, redeemed status) and authentication requirement. For a simple tool with 3 parameters, this is complete and sufficient.

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 coverage is 100% with adequate descriptions. The description adds context for the admin_key ('Worker secret ADMIN_KEY') and reinforces the redeem behavior, but does not significantly extend beyond the schema. Baseline 3 is appropriate.

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?

Description uses specific verb 'validate' and resource 'reward code', clearly indicating the action. It distinguishes from sibling tools (all lesson/course-related) by specifying the context (Capital Factory gift shop) and the code formats (GT- or FG-).

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?

Description identifies the target user ('OPERATOR') and the context (gift shop), implying when to use. It does not explicitly state when not to use, but sibling tools are unrelated, so no alternatives are needed. A clear usage context is provided.

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