send_text_message

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

No annotations are provided, so the description bears full responsibility for behavioral disclosure. It clearly indicates the action (sending a message), but it does not disclose potential side effects, permission requirements, rate limits, or handling of missing recipient fields. For a mutation-like operation, this lack of context leaves significant behavioral ambiguity.

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 very concise: one sentence for purpose, followed by a compact Args list. Every line provides essential information without fluff. The use of a bullet-like format (though in plain text) is clean and easy to parse. It earns its place entirely.

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 simple send-message tool with an output schema, the description covers all parameters adequately. However, it lacks any contextual information about prerequisites (e.g., at least one recipient field must be set) or integration with authentication, and does not address sibling tool distinctions. The presence of an output schema reduces the need to explain return values, but the missing usage context makes it only minimally complete for an agent to confidently select it over alternatives.

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 0%, but the description fully compensates by explaining every parameter: to_user (userid, multiple via '|'), to_party (dept id), to_tag (tag id), content (text), agent_id (leave empty for default). It adds critical formatting details like the '|' separator and default behavior for agent_id, which the schema completely lacks. This is excellent parameter documentation.

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 purpose: '向企业微信成员发送文本消息' (send text messages to WeCom members). This provides a specific verb and resource. However, it does not explicitly distinguish itself from sibling tools like send_message or mass_send_message, relying on the word '文本' (text) to imply its scope. The tool name already conveys this, so slightly less credit for differentiation.

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?

There is no guidance on when to use this tool versus the siblings (send_markdown_message, send_file_message, mass_send_message, etc.). The description only states what it does, not when it should be preferred. No exclusions or alternatives are mentioned, so it provides minimal usage context.

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