reactions_removeRemoves an emoji reaction the bot previously added to a Slack message, letting you undo or clean up bot reactions.
Remove an emoji reaction the bot previously added to a message.
| Name | Required | Description | Default |
|---|---|---|---|
| ts | Yes | Timestamp of the message | |
| emoji | Yes | Emoji name without colons, e.g. thumbsup, eyes, white_check_mark | |
| channel | Yes | Channel ID, #channel-name, or user (ID, @handle, email) for a DM |
Changes observed during successful MCP inspections.
v0.6.1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare destructiveHint=true, idempotentHint=true and openWorldHint=true, so the safety profile is covered structurally. The description adds one genuinely useful behavioral constraint beyond them — that only the bot's own reactions qualify — but says nothing about what happens on failure (e.g., reaction absent) or whether removal triggers notifications.
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?
One sentence, front-loaded with the verb and resource, with zero filler. Nothing could be cut without losing the scope constraint.
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?
For a simple three-parameter mutation with complete schema docs, full annotation coverage and no output schema, the description covers what is needed to call it correctly. The only gap is failure-mode behavior when the reaction is not present.
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% and all three parameters carry their own docs, including the emoji-without-colons format. The description adds no parameter-level detail, so this sits at the baseline for a fully documented 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?
States a specific verb (Remove) and resource (an emoji reaction) with a meaningful scope constraint: only reactions the bot previously added. That scope distinguishes it from a general reaction-removal or from reactions_add, though it never names the sibling tool directly.
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?
Usage is implied rather than stated: the 'previously added by the bot' clause tells the agent this is the undo path for reactions_add, but there is no explicit when-to-use, when-not-to-use, or named alternative. An agent must infer that it cannot be used to remove other users' reactions.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.