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

No annotations are provided, so the description carries the full burden. It discloses that the operation is read-only ('Read-only, spends nothing'), requires an api_key, and is paginated. It doesn't disclose details like rate limits or error behavior, but the key behavioral traits (safety, cost, pagination) are covered. The 'spends nothing' note is particularly valuable for an agent deciding whether to call this tool.

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 English portion is dense and front-loaded with the core purpose, followed by usage routing. The Vietnamese repetition at the end is redundant for an English-speaking agent and adds length without new information, which prevents a 5. However, the structure is otherwise efficient and every English 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 paginated list tool with no output schema, the description covers the essential context: what it returns, that it's read-only, that it costs nothing, and how to follow up. It doesn't describe the response format or pagination details beyond 'paginated', but the output schema absence is partially mitigated by the field list. The main gap is not describing what happens with invalid api_key, but overall this is quite complete for its complexity.

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 schema already documents all three parameters (page, limit, api_key). The description adds the context that api_key is required and that pagination exists, but doesn't add meaning beyond what the schema provides. Baseline 3 is appropriate when the schema does the heavy lifting.

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 ('List'), a resource ('your recent orders'), and the exact fields returned (order_code, product, quantity, total paid, status, date). It also explicitly distinguishes itself from wallet_history, which is a sibling that could be confused with it. This is a clear, specific purpose statement.

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 provides explicit WHEN TO USE guidance ('the user wants their purchase history or you need to find an order_code'), explicit AFTERWARDS routing to check_order_status and get_mail_code, and explicit PREFER INSTEAD guidance to use wallet_history for money movements. This is exemplary usage guidance with both positive and negative selection criteria.

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