im_send_message

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

No annotations are provided, so the description must carry the full behavioral disclosure burden. It only states the tool sends messages and lists supported types. It fails to mention authentication requirements, side effects (e.g., message delivery), response behavior, or error scenarios. This is a significant gap for a write operation.

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 a single, front-loaded sentence that conveys the core purpose and supported types without waste. Every word adds value, and it is appropriately sized for a straightforward tool.

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?

With no output schema and no annotations, the description is brief but covers the basic action. However, it omits expected return values (e.g., message_id) or possible constraints (e.g., message size limits). Given the tool's simplicity and full schema coverage, it is minimally viable but lacks depth for robust decision-making.

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 coverage is 100%, so the baseline is 3. The description's mention of message types ('文本、富文本、卡片等') partially aligns with the msg_type enum but adds no new meaning beyond the schema. It does not clarify content formatting or receive_id_type semantics.

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 verb ('发送' / send) and resource ('飞书消息' / Feishu message), and mentions supported types (text, rich text, cards). This distinguishes it from sibling tools like im_list_messages (list) and im_create_chat (create chat).

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 usage for sending messages but does not explicitly state when to use this tool versus alternatives like im_list_messages or im_create_chat. It offers no exclusions or context about prerequisites, making the guidance only implicit.

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