users_create_dm

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

Annotations already include idempotentHint=true, and the description reinforces with 'Idempotent: repeat calls return the same DM channel id.' It also discloses the endpoint is user-scoped, does not accept audit_reason, and specifies the return payload shape. This adds significant behavioral context beyond the annotations, with no contradictions.

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?

Well-structured with bold section headers (Purpose, When to use, Idempotent, Note, Returns). The description is compact, every sentence serves a distinct purpose, and the most important information (purpose) is front-loaded. No wasted words.

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 single-parameter tool with an output schema, the description is complete. It covers the endpoint, usage context, idempotency, restrictions (no audit_reason), and return value fields. Even without the output schema, the description tells the agent exactly what to expect and how to proceed.

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% with a single parameter 'recipient_id' described as 'User to DM'. The description adds minimal extra meaning by mentioning 'between the bot and a user' and the return field recipient_ids, but the schema already fully documents the parameter. Baseline of 3 is appropriate as the description is not needed to compensate.

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 opens with a specific verb and resource: 'Open (or fetch) a DM channel between the bot and a user', and even includes the API endpoint. It clearly distinguishes this from sibling tools like messages_send or users_get by focusing on DM channel creation.

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?

Explicitly states when to use: 'Send a private message to a user - Discord requires a DM channel id first.' This gives clear context and implies that this step is a prerequisite for sending DMs, which effectively tells the agent when this tool is needed.

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