users_create_dm

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

The description adds value beyond the annotations by noting the user-scoped nature, that audit_reason is not accepted, and that repeated calls return the same channel ID. It also clarifies the open-or-fetch semantics, which complements the idempotentHint and readOnlyHint annotations without contradicting them.

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 highly structured with bold headers, front-loads the purpose, and every sentence earns its place. It is compact yet covers purpose, usage, idempotency, scope, return value, and the next step.

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 the annotations, the 100% schema coverage, and the presence of an output schema, the description is complete for correct invocation. It even explains how to use the returned channel_id with messages_send, which would otherwise require cross-tool inference.

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 100%, so the baseline is 3. The description does not add much parameter-specific meaning beyond identifying the user/recipient context; the consent-related parameters are only explained in the schema. This is adequate but not enhanced.

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 names the exact endpoint. This clearly distinguishes it from sibling tools like messages_send by framing it as the prerequisite channel-opening step.

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 'When to use' section explains the exact scenario: sending a private message requires a DM channel ID first. It does not explicitly list when-not-to-use or alternatives, but the guidance is clear enough for an agent to select it over message-sending siblings.

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