discord_send_dm

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

Discloses key behaviors beyond annotations: requires bot-user shared server, user DM settings, and returns the new message ID. Annotations (readOnlyHint=false, destructiveHint=false) are consistent, and description adds actionable context about failure conditions.

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?

Three sentences front-load key info: purpose, usage guidance, and return value. No redundant or irrelevant 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?

For a simple tool with two parameters, no output schema, and clear annotations, the description covers all necessary context: what it does, when to use it (and alternatives), prerequisites, failure mode, and return value.

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 baseline is 3. Description adds value by clarifying content is 'Plain-text body' and specifying max 2000 characters, which is useful semantic detail beyond the schema's generic 'string' type.

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 private direct message') and the target ('a user by their user ID'). It explicitly distinguishes from sibling tool discord_send_message by stating to use that for server channels.

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?

Provides explicit guidance on when to use this tool vs. discord_send_message, and lists prerequisites (bot must share server, user must allow DMs) with the consequence of failure ('otherwise Discord rejects the send').

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