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

With no annotations provided, the description carries the full burden. It explicitly states 'KHÔNG trừ tiền' (does NOT deduct money), which is a critical behavioral fact. It also discloses the return payload including the confirm_token, indicating the operation is non-final and safe.

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 content is front-loaded with the English summary, but it repeats the same information in Vietnamese, doubling the length. The core behavior could be conveyed in one sentence; the duplication is redundant for an AI agent.

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?

Since there is no output schema, the description usefully lists return values: unit price, discount, total in VND, balance, stock, and confirm_token. It also covers the workflow position, the non-charge guarantee, and the required next step (ask confirmation then buy_product). Minor missing details like quote expiration or failure cases prevent a top score.

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 does not add meaningful parameter-level detail beyond what the schema already provides for api_key and product_id; it only refers to 'a product' generically.

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 uses a specific verb and resource: 'get a price quote for a product BEFORE purchasing.' It clearly differentiates this from sibling buy_product by stating it is STEP 1, does NOT deduct money, and returns a confirm_token for later confirmation. Both English and Vietnamese reinforce the same unambiguous purpose.

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 places the tool in a workflow ('STEP 1 of buying') and explicitly instructs the agent to ask the user for confirmation before calling buy_product, naming the relevant sibling. It does not exhaustively list when not to use alternatives, but the 'before purchasing' and 'does not deduct money' signals make the usage context clear.

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