Add users to a Pumble channel by channel name or ID and user names, emails, or IDs, resolving identifiers automatically.
Add users to a channel by names or emails. Resolves entities natively.
| Name | Required | Description | Default |
|---|---|---|---|
| userIdentifiers | Yes | Array of user names, emails, or IDs to add. If not provided, MUST ASK. DO NOT GUESS. | |
| channelIdentifier | Yes | Channel name, slug, or ID. If not provided, MUST ASK. DO NOT GUESS. |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden of behavioral disclosure, but 'Resolves entities natively' is opaque jargon that does not explain what happens if a name is ambiguous, if a user is already a member, or whether the operation is idempotent. Permissions, partial-failure behavior, and reversibility are all absent.
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?
Two short sentences with the core action front-loaded and no filler. The second sentence is vague enough ('natively') that it earns only partial credit, but there is no wasted bulk.
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 two-parameter mutation with a fully documented schema, the essentials are present, but with no annotations and no output schema the description should say what a successful call returns or how duplicate/ambiguous users are handled. It is minimally viable rather than complete.
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 coverage is 100%, so the schema already documents both parameters thoroughly, including the 'MUST ASK. DO NOT GUESS.' constraint. The description adds nothing beyond restating identifier types, and actually omits IDs, so the baseline 3 is appropriate.
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 and resource (add users to a channel) plus the resolution mode, which separates it from remove_user_from_channel_via_name_or_id. However, it says 'by names or emails' while the tool name and schema also support IDs, leaving the accepted identifier forms slightly inconsistent.
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 when-to-use, when-not-to-use, or alternative is named. The sibling remove_user_from_channel_via_name_or_id is the obvious counterpart but is never referenced, and prerequisites (membership, permissions, whether the channel must already exist) are unstated.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.