Resume Existing Claude Code Session

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

No annotations are provided, so the description must carry the burden of disclosing side effects, prerequisites, and lifecycle behavior. It only states the binding action and one parameter requirement, omitting whether resuming modifies the current companion state, launches tmux, or has destructive implications. This is a significant gap for a tool with 18 parameters.

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 sentences, front-loaded with the action and followed by a key usage pattern. No wasted words; it is appropriately compact for the purpose it serves.

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?

With 18 parameters, no output schema, and no annotations, the description is far too thin. It does not explain what happens on resume, what the tool returns, potential side effects, or how it differs from sibling resume tools. The agent is left to infer these from parameter names and schema descriptions, which is risky for such a complex 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?

Schema coverage is 100%, so the baseline is 3. The description adds cross-parameter value by explicitly tying sessionId and continueLatest to specific backends, which is not immediately obvious from scanning the schema descriptions independently. This helps the agent select the right parameter combination.

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 starts with 'Bind cc-in-codex to an existing Claude Code conversation,' which clearly states the verb and resource. The second sentence adds backend-specific nuance (SDK vs TUI), but it does not explicitly differentiate from the sibling tool companion_tui_resume, which may cover a TUI-only resume path.

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 explicit usage guidance by backend: 'SDK needs sessionId; TUI can use sessionId or continueLatest:true.' This tells the agent what parameter is required in each mode. However, it does not explicitly state exclusions or when to use a different companion tool (e.g., companion_start for new sessions).

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