send_group_message

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 a key behavioral dependency: media types require upload_media to obtain a mediaId. However, it does not mention any side effects, required permissions, failure modes, or response format. For a send operation, additional disclosure about potential errors or the nature of the operation (irreversible write) would be valuable.

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 sentences long. The first sentence states the action and lists capabilities; the second provides an essential prerequisite. There is no redundancy or filler; every 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 tool with 21 parameters and conditional logic, the description covers the core message types and the upload prerequisite. It doesn't explain actionCard button configurations or parameter interdependencies, but those are already detailed in the schema. The lack of an output schema means a note about the return value would be helpful, but it is not a critical gap.

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?

The schema has 100% parameter coverage with detailed descriptions, so the baseline is 3. The description adds value by explaining the mediaId prerequisite for image/file/audio/video, which clarifies the origin of several parameters. It also succinctly enumerates message types, helping agents understand how to pick the right msgtype and corresponding fields.

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 action: 'Send a message to a DingTalk group chat.' It lists supported message types (text, markdown, image, link, actionCard, file, audio, video), which specifies the scope. The mention of 'group chat' distinguishes it from sibling send_single_message, and the reference to upload_media as a prerequisite clarifies its 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 provides clear context: it is for sending messages to a DingTalk group chat. It also gives an explicit usage prerequisite: 'Use upload_media first for image/file/audio/video to get a mediaId.' While it doesn't explicitly state when not to use it (e.g., for single messages), the group-chat framing and sibling names imply the boundary.

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