Narrow the Slack sidebar to matching channels or users by typing a filter query; pass an empty string to clear it. Requires the Home tab open.
Type into the sidebar's channel and user filter, narrowing the visible list. Pass an empty string to clear the filter. The Home tab must be showing (call show_home first).
| Name | Required | Description | Default |
|---|---|---|---|
| query | Yes | Channel or user name fragment, or empty to clear. |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full behavioral burden and does disclose the UI state prerequisite and the empty-string clearing behavior. However, it never says whether the filter is ephemeral or persisted, what happens if Home is not showing (silent failure vs. error), or whether it affects other clients — meaningful gaps for a UI-driving tool.
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?
Three short sentences, front-loaded with the action and effect, then the clearing rule, then the prerequisite. No filler; every sentence earns its place.
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 one-parameter UI filter with no output schema and no annotations, the description covers the action, the clearing case, and the required screen state, which is close to what an agent needs. It stops short of describing failure behavior when the prerequisite is unmet or whether the filter state persists.
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 the single parameter is already documented as 'Channel or user name fragment, or empty to clear.' The description's empty-string sentence largely restates the schema, so the baseline of 3 applies.
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 ('type into the sidebar's channel and user filter') plus the observable effect ('narrowing the visible list'), so an agent knows exactly what the tool manipulates. It does not explicitly contrast itself with other Slack navigation tools beyond naming show_home as a prerequisite, which keeps it just short of a 5.
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?
Gives a concrete prerequisite ('The Home tab must be showing (call show_home first)') and names the sibling tool that satisfies it, plus a clear condition for the empty-string case. No explicit when-not-to-use guidance, but the routing context is clear.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.