send_dm

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

No annotations are provided, so the description carries the full burden for behavioral disclosure. It only states the basic action and parameter method, but does not mention potential errors (e.g., user not found, DMs closed), rate limits, or side effects. This is a significant gap for a write operation.

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 a single, clear sentence that front-loads the action and target. Every word earns its place; there is no wasted content.

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?

The tool is simple with full schema coverage, but the absence of annotations and any usage caveats leaves the description minimally adequate. For a mutation tool, it would benefit from noting prerequisites (e.g., mutual connection) or failure behaviors, but the current description is not misleading.

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%, so the baseline is 3. The description's 'by their ID' adds minimal value by reiterating the user_id parameter, but it does not add formatting, examples, or context beyond the schema descriptions. No credit for repeating what's already in the schema.

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 direct message') and the target ('to a user by their ID'). It distinguishes from siblings like send_message (which likely sends to a channel) by specifying 'direct message' and 'user ID'.

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 implies usage for sending DMs to users, and the 'by their ID' hints at the parameter. However, it does not explicitly name alternatives or state when not to use it (e.g., for channel messages use send_message). Context from sibling tools makes it inferable, but the guidance is not explicit.

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