create_direct_message

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

Annotations indicate non-read-only and non-destructive. The description adds that it sends a DM and requires attachments, which is useful beyond annotations. However, it omits side effects, permissions, or response behavior.

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 brief with two sentences, front-loading the main action. It is efficient but could benefit from structuring key points (e.g., requirements, optional fields).

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 6 parameters (including nested objects and complex features like from_message_type) and no output schema, the description is insufficient. It does not explain how recipients are resolved, return values, or behavior for different from_message_type values.

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 high (83%), so the schema provides clear descriptions for most parameters. The description reiterates the need for transcript or links but does not clarify complex parameters like 'from_message_id' or nested 'to' object beyond schema info.

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 it sends a Direct Message to a user or group, specifying the verb 'Send' and resource 'Direct Message'. It distinguishes from sibling tools like create_conversation_message by focusing on DM specifically.

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 mentions a requirement (must provide transcript or link attachments) but provides no guidance on when to use this tool versus alternatives like create_conversation_message or add_attachments_to_message. No contextual examples or exclusions.

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