discord_send_dm

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

Annotations indicate this is not read-only or destructive. The description adds that it returns the new message ID and notes that Discord may reject the send if conditions are not met. While it could mention rate limits, it provides sufficient behavioral context beyond annotations.

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 concise sentences: first sentence states the primary action, second provides alternative, third covers prerequisites and return value. No redundant information.

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 DM tool with two parameters and no output schema, the description covers purpose, differentiation, prerequisites, and return. It does not mention rate limits or permission inheritance, but overall it is sufficiently complete for effective agent usage.

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?

Input schema has 100% coverage with detailed descriptions for both parameters (user ID snowflake, content max 2000 chars). The description does not add new parameter information but reinforces the return value. Baseline 3 is appropriate.

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 resource ('a user by their user ID'). It also distinguishes from the sibling tool discord_send_message by specifying that the latter is for server channel posts.

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 versus alternatives ('Use discord_send_message to post in a server channel instead') and lists prerequisite conditions ('Requires the bot to share at least one server... the user must allow DMs from server members').

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