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 the optional file attachment capability (up to 10 files), which is useful context. However, it fails to disclose critical behavioral traits: whether this is a read-only or destructive operation (it's clearly a write operation), potential rate limits, authentication requirements, error conditions, or what happens on success (e.g., returns a message ID). The description is minimal and leaves significant gaps.

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 and includes the key optional feature. There's no wasted language or redundancy, making it highly concise and well-structured for quick understanding.

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 complexity of a message-sending tool with 5 parameters, no annotations, and no output schema, the description is incomplete. It doesn't cover behavioral aspects like permissions, rate limits, or response format, nor does it provide usage guidelines. For a tool that performs a write operation in a chat platform, more context is needed to ensure safe and effective 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 fully documents all 5 parameters. The description adds marginal value by mentioning the optional file attachment feature, which aligns with the 'files' parameter. However, it doesn't provide additional semantic context beyond what's in the schema, such as explaining interactions between parameters or usage examples.

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 message') and target ('to a Discord channel'), with an optional feature ('with up to 10 files'). It distinguishes from siblings like discord_edit_message or discord_delete_message by focusing on message creation. However, it doesn't explicitly differentiate from discord_create_dm, which might also send messages but to DMs rather than 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?

The description provides no guidance on when to use this tool versus alternatives. For example, it doesn't mention when to choose discord_send_message over discord_edit_message for updates, or discord_create_dm for direct messages. There's also no information about prerequisites, such as needing channel access or bot permissions.

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