mcp-discord-bridge

add_reaction

Add an emoji reaction to a specified message in a Discord channel using the channel ID, message ID, and emoji.

Instructions

Add an emoji reaction to a message

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "channel_id": "<channel_id>",
      "message_id": "<message_id>",
      "emoji": "<emoji>"
    },
    "name": "add_reaction"
  }
}

Input Schema

Name	Required	Description
`channel_id`	Yes
`message_id`	Yes
`emoji`	Yes	Emoji to react with (unicode or custom format)

Schema Changelog

Changes observed during successful MCP inspections.

First observedMay 25, 2026

TDQS

C2.4/5.0

Behavior1/5

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

With no annotations, the description is the sole source of behavioral info, but it only states the basic action. Missing details like permissions needed, whether it overrides existing reactions, rate limits, or error conditions.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness3/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Single sentence with no wasted words, but severely under-informative. Appropriate length for a simple action, but lacks necessary detail.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness1/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

No output schema is provided and description gives no information about return values, side effects, or any behavioral context beyond the basic action.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters1/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is only 33% (only 'emoji' has a description). The tool description does not add any further meaning to 'channel_id' or 'message_id' beyond the schema types.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the action ('Add') and the resource ('an emoji reaction to a message'), distinguishing it well from siblings like 'add_multiple_reactions' and 'remove_reaction'.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines2/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

No guidance on when to use this tool versus alternatives (e.g., 'add_multiple_reactions' for multiple reactions, or whether it should be used before or after other actions).

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