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

With annotations already declaring readOnlyHint=false and idempotentHint=true, the description adds meaningful extra context by clarifying that 'New issuance is a mutation; an existing receipt remains readable in read-only mode.' It also discloses the auth requirement, adding value 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?

Two short sentences deliver the essential behavior, the usage precondition, and the token requirement with no filler. 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?

For a zero-parameter tool with no output schema, the description covers the core semantics: issuance vs. read-only retrieval, the mutate/read distinction, and the required credential. No critical information is missing for invoking it 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 tool has 0 parameters and schema coverage is effectively 100%, so there is no parameter burden on the description. The baseline for zero-parameter tools is 4, and the description adds relevant behavioral context without needing to explain schemas.

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 verb+resource pair ('Get or issue your participation-only Candy receipt') and adds the condition 'after one consume and honest outcome.' It is clear, though it does not explicitly differentiate from siblings; no sibling appears to offer receipt functionality.

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 gives a clear usage context ('after one consume and honest outcome') and the prerequisite ('Requires the Candy bearer token.'). It does not spell out when not to use it, but the context is sufficient for an agent to select it correctly.

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