list_purchases

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

No annotations are provided, so the description carries the burden. It discloses that the tool returns 'last plus purchases[]', mentions testMode behavior ('gray test coins'), and warns against misinterpreting the idiom as a product name. It doesn't detail pagination or error behavior, but the key behavioral traits are covered.

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 compact and front-loaded with the core purpose, then gives trigger phrases and follow-up actions. Every sentence adds value, though the parameter semantics gap means it's not perfectly complete. Still, it's well-structured and not verbose.

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 complexity (3 optional params, no output schema), the description covers the main use case, trigger phrases, and follow-up action. It doesn't explain return structure beyond 'last plus purchases[]' or parameter meanings, but for a list tool with clear purpose, it's mostly complete. The missing parameter semantics and lack of output schema details prevent a 5.

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%, so the description must compensate. It doesn't explain the three parameters (limit, storeId, category) at all. However, the tool's core purpose is clear enough that an agent could infer limit is for count, but storeId and category remain unexplained. This is a gap, but the description's focus on usage context partially compensates.

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 lists the owner's recent AgentPay purchases with line items, and it distinguishes itself from siblings like create_purchase and search_products. The verb 'list' plus the resource 'purchases' is specific and unambiguous.

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 explicitly lists trigger phrases ('как обычно', 'то же самое', etc.) and instructs to call it when the user refers to a previous order. It also provides a clear alternative: 'Check catalog price then create_purchase', and warns not to search the idiom as a product name. This is excellent routing guidance.

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