kb_answer

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 tool uses the Retrieve API and only returns search results (no answer generation). This is clear, though it could mention that the operation is read-only and does not modify any data.

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 short, front-loaded sentences that convey purpose and behavior without unnecessary detail. Every sentence adds value.

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, clear purpose) and the presence of an output schema (which covers return structure), the description is complete enough. It explains what the tool returns (relevant document chunks) and its non-generative nature.

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 both parameters adequately. The description does not add additional meaning beyond what is in the schema (e.g., constraints or context for max_results range). Baseline score of 3 applies.

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 searches Amazon Bedrock Knowledge Base and returns relevant document chunks. It explicitly distinguishes itself from generative tools by stating it does not generate answers (回答生成は行わず、検索結果のみを返す).

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 implies the tool is for retrieval-only queries, but it does not provide explicit guidance on when not to use or alternatives. Since there are no sibling tools, the lack of exclusion is acceptable, but it could be more explicit about prerequisites or limitations.

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