start_session

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

With no annotations, the description carries the full burden, but it only shares basic behavior: starting a PTY command and default cwd. It omits critical details like session persistence, resource consumption, blocking nature, or that sessions need to be closed.

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 main purpose. Every sentence adds value: purpose, default behavior, return value. No redundant or irrelevant details.

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?

Despite good purpose clarity, the description lacks context for a complex interaction tool. No mention of how to interact via sibling tools (send_text, read_output), lifecycle management, error handling, or environment. The return value is specified, but behavioral guidelines are missing.

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 0% (no parameter descriptions), so the description must compensate. It clarifies cwd's default but says nothing about command structure, cols, or rows, leaving their meaning and constraints (e.g., terminal dimensions) unexplained.

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 starts any CLI program in a managed PTY within the project, with a specific verb and resource. It distinguishes from sibling tools like close_session or list_sessions, as it initiates a session.

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 implies use for starting a new CLI session but does not explicitly provide when to use or when not to use it, nor does it mention alternatives among the sibling tools. Usage context is only implicit.

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