Discord MCP Server

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It mentions 'full attachment details,' which adds context about return data, but lacks critical information such as authentication requirements, rate limits, error conditions (e.g., if the message doesn't exist), or whether this is a read-only operation (implied by 'Get' but not explicit).

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 useful detail ('with full attachment details'). There is no wasted verbiage, 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 parameters, no output schema, no annotations), the description is somewhat complete but has gaps. It covers the basic purpose and hints at return data, but without annotations or output schema, it should ideally mention behavioral aspects like read-only nature or error handling to be fully adequate for agent use.

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%, so the schema already documents both parameters (channelId and messageId) adequately. The description adds minimal value beyond the schema by implying the tool retrieves a message using these IDs, but it doesn't provide additional semantics like format examples or constraints beyond what's 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 ('Get') and resource ('a specific message by ID'), distinguishing it from siblings like discord_get_message_history (which retrieves multiple messages) and discord_search_messages (which searches). However, it doesn't explicitly contrast with discord_get_channel, which might also retrieve messages indirectly, leaving some ambiguity.

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?

No explicit guidance on when to use this tool versus alternatives like discord_get_message_history or discord_search_messages is provided. The description implies usage for retrieving a single known message ID, but it doesn't state prerequisites (e.g., needing channel access) or exclusions (e.g., not for bulk retrieval).

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