List tmux panes with their IDs, titles, current directories, running commands, and sizes. Filter by session or omit it to see panes from all sessions and monitor coding agents.
List panes (id, title, cwd, running command, size). Titles are what agents_launch set.
Omit session to list every visible session.
| Name | Required | Description | Default |
|---|---|---|---|
| session | No |
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |
Changes observed during successful MCP inspections.
v0.1.1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the behavioral disclosure burden. It reveals the output shape, states that titles are set by agents_launch, and clarifies that omitting session lists every visible session. While it does not explicitly say 'no side effects,' the verb 'list' strongly implies a read-only operation, and the added cross-tool detail about titles is genuinely useful.
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?
The description is two concise sentences with no filler. The core purpose and output fields are front-loaded, and the second sentence efficiently covers the parameter's behavioral nuance.
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?
Given the tool's low complexity, the optional session parameter, and the presence of an output schema, the description is nearly complete. The only minor gap is that it does not explicitly state what value session expects (e.g., session name vs. ID), but this is not critical for understanding the listing behavior.
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?
The schema only documents the session parameter's name, type, and default null, with 0% description coverage. The description compensates by explaining the omission behavior ('Omit session to list every visible session'), which adds meaning beyond the schema; the inverse behavior for a supplied session is implied but not explicitly described.
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?
The description uses the specific verb 'List' with the resource 'panes' and enumerates the returned fields (id, title, cwd, running command, size), making the tool's purpose unambiguous. It is clearly distinguishable from siblings like pane_read, pane_send, and pane_kill by being a read-only listing operation.
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?
The description gives clear context for when to use the tool and explains the default behavior: 'Omit session to list every visible session.' It does not explicitly name alternatives or exclusion conditions, but the listing semantics already disambiguate it from the action-oriented sibling tools.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.