Discord MCP Server

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

No annotations are provided, so the description carries full burden. It mentions 'full attachment details' as a behavioral trait, which is useful. However, it lacks critical information: whether this is a read-only operation (implied but not stated), rate limits, authentication requirements, error handling (e.g., if message doesn't exist), or response format. For a tool with zero annotation coverage, this is insufficient.

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 front-loads the core purpose ('Get a specific message by ID') and adds a key detail ('with full attachment details'). There is no wasted verbiage or redundancy, making it highly concise and well-structured.

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 low complexity (2 simple parameters, no output schema, no annotations), the description is minimally adequate. It covers the basic purpose and a key feature (attachment details), but lacks behavioral context (e.g., safety, errors) and usage guidance. With no output schema, it doesn't explain return values, which is a gap for 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?

Schema description coverage is 100%, with clear descriptions for both parameters (channelId and messageId). The description adds no parameter-specific information beyond what the schema provides, such as format examples or constraints. Since the schema does the heavy lifting, the baseline score of 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 ('Get') and resource ('a specific message by ID'), specifying it retrieves full attachment details. It distinguishes from siblings like discord_get_message_history (which retrieves multiple messages) and discord_list_attachments (which lists attachments separately). However, it doesn't explicitly contrast with discord_search_messages or discord_get_channel, which could also retrieve messages indirectly.

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 when to prefer discord_get_message over discord_get_message_history (for single vs. multiple messages), discord_search_messages (for searching vs. direct ID lookup), or discord_list_attachments (for attachments only vs. full message). No prerequisites or exclusions are stated.

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