Resume Existing Session In Visible TUI

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It discloses the primary behavior (launching a visible tmux CLI) but does not mention side effects such as replacing existing panes, permission implications, or how the binding behaves. It is not misleading, but it is minimal.

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 a single, well-structured sentence with no redundant words. It front-loads the key action (launching the CLI) and clearly communicates the resume/continue options. Every word 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 tool with 18 parameters, no output schema, and no annotations, the description is too sparse. It does not explain the tool's role in the companion workflow, what happens after launch (e.g., does it block, return a session ID?), or how it relates to the many sibling tools. The schema is rich, but the description alone is insufficient for an agent to fully understand the tool.

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 input schema provides 100% description coverage for all 18 parameters, so the description need not add parameter details. It does not, but the high schema coverage establishes a baseline of 3. The description adds no additional parameter semantics beyond the 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?

The description clearly states the tool launches a visible tmux-hosted Claude Code CLI with `--resume <sessionId>` or `--continue` and binds it to the project companion. This uses a specific verb+resource and distinguishes it from siblings like companion_tui_open (new session) and companion_resume (non-TUI).

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 does not provide any guidance on when to use this tool versus alternatives. It simply states what it does, without indicating context, prerequisites, or exclusions. Sibling names suggest related tools but are not referenced, leaving the agent to infer usage.

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