msteams-personal-mcp

teams_add_reaction

Adds an emoji reaction to a Teams chat message so everyone in the conversation sees it. Use only when the user asks to react, with a conversation ID, message ID, and emoji.

Instructions

React to a message with an emoji, visible to everyone in the chat. Only when the user asked to react. emoji can be a key ("like", "heart", "1f440_eyes") or the emoji itself ("👍"). See teams_list_reaction_emojis.

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": {
      "conversationId": "<conversationId>",
      "messageId": "<messageId>",
      "emoji": "<emoji>"
    },
    "name": "teams_add_reaction"
  }
}

Input Schema

Name	Required	Description	Default
`emoji`	Yes
`messageId`	Yes
`conversationId`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.9.0Oct 23, 2026

TDQS

A4/5.0

Behavior4/5

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

Annotations already declare a non-destructive mutation with openWorldHint, but the description adds the non-obvious fact that the reaction is publicly visible to everyone in the chat, plus a consent condition. It omits what happens on a duplicate reaction or any failure behavior.

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

Conciseness5/5

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

Three short sentences, front-loaded with the action and visibility, followed by the usage guard and the parameter format. Every sentence adds information with no repetition.

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

Completeness4/5

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

For a simple mutation with no output schema, the description covers action, visibility, consent condition, emoji encoding, and a helper tool reference. The only gaps are duplicate-reaction behavior and the semantics of the two ID parameters, which are minor for this operation's complexity.

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

Parameters3/5

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

Schema description coverage is 0% across three required params, so the description carries weight: it explains the emoji format (key like '1f440_eyes' or literal '👍') and points at the enumerating tool. conversationId and messageId get no explanation beyond self-evident naming, leaving the compensation incomplete.

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

Purpose4/5

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

States a specific verb+resource ('React to a message with an emoji') and adds meaningful scope ('visible to everyone in the chat'), which separates it from teams_remove_reaction without naming the sibling. Not quite a 5 because no sibling is explicitly contrasted.

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

Usage Guidelines4/5

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

'Only when the user asked to react' is an explicit usage guard, and it routes to teams_list_reaction_emojis for valid emoji keys. It does not mention teams_remove_reaction as the inverse operation, so the when-not side is only partially covered.

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