Discord MCP Server

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

No annotations are provided, so the description carries the full burden. It mentions the tool can 'create or get existing' a DM, which hints at idempotent behavior, but lacks details on permissions required, rate limits, error conditions (e.g., invalid user ID), or what happens if the user is not reachable. For a tool that interacts with user channels, this is a significant gap in behavioral context.

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, efficient sentence that directly states the tool's function without any fluff. It is appropriately sized and front-loaded, making it easy to parse quickly.

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 tool's moderate complexity (creating or retrieving a DM channel), lack of annotations, and no output schema, the description is minimally adequate. It covers the basic purpose but misses behavioral details like return values (e.g., channel ID or error messages), which are crucial for an agent to use it effectively. This leaves gaps in completeness.

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?

The description adds no specific parameter information beyond what the schema provides (100% coverage with a clear 'userId' description). However, with only one parameter and high schema coverage, the baseline is strong. The description's focus on 'with a user' implicitly reinforces the userId parameter's role, but doesn't add new semantics. A score of 4 reflects that minimal compensation is needed given the simple 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 verb ('create or get') and resource ('DM channel with a user'), making the purpose specific and understandable. It doesn't explicitly distinguish from sibling tools like 'discord_get_dm_channels' (which likely lists all DMs) or 'discord_get_channel' (which might retrieve any channel), but the focus on a single user DM is reasonably clear.

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 provides no guidance on when to use this tool versus alternatives. It doesn't mention prerequisites (e.g., needing to be friends with the user), when to prefer it over 'discord_get_dm_channels' for existing DMs, or any exclusions. Usage is implied but not explicitly stated.

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