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

Annotations are empty, so the description carries the full burden. It discloses key behavioral traits: items come from a demonstration catalog, are examples rather than the full inventory, and no pricing is returned. These are non-obvious and important for setting expectations. It does not mention read-only status or auth, but for a search/show tool this is sufficient.

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 every sentence adds value. It is concise and well-structured, avoiding redundancy or fluff.

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's simplicity (2 parameters, no output schema), the description covers the essential context: what the tool does, its limitations, and when to use an alternative. It explains the return type (examples, no pricing) and points to check_coverage for definitive answers, making it complete for an agent to use 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?

Schema description coverage is 100%, so the baseline is 3. The description adds little beyond the schema; it emphasizes 'one country' but does not provide extra syntax or format details beyond what the schema already supplies. The parameters are adequately documented in the schema, so this is acceptable.

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's function: 'Show example rewards available in one country.' It also distinguishes itself from siblings by noting it provides examples rather than the full inventory and directs to check_coverage for definitive answers. This is a specific verb+resource+scope construction that leaves no ambiguity.

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?

Explicit usage guidance is provided: 'Call this when someone asks what kind of thing is on offer, or wants to see the catalog for a country.' It also gives an alternative: 'Use check_coverage for the definitive answer about what a country supports.' This clearly defines when to use the tool and when not to.

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