open_session

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

No annotations are provided, so the description must disclose behavior. It mentions opening a terminal app with priority and ownership restriction, but it does not explain side effects (e.g., whether it creates a new window, affects existing sessions) or the exact behavior beyond that.

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 relatively short and includes arg/return sections. However, it wastes space listing the priority and including a contradiction about required parameters, making it less efficient than it could be.

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?

Output schema exists (though not shown) and the description lists return fields, but it lacks context on parameter meaning, usage scenarios, and side effects. The 0% schema coverage makes the incomplete description a significant gap.

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% with no parameter descriptions in the schema. The description provides only vague names for agent_id and caller_agent_id, and contradicts the schema by stating caller_agent_id is required when it is actually optional with a default null.

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 opens the agent's tmux session in a terminal app with a priority order. It uses specific verb and resource, distinguishing it from sibling tools like send_command or get_output which do not launch terminal windows.

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?

No explicit guidance on when to use versus alternatives, but the tool's purpose is intuitive. The restriction 'Only Owner can use' provides some usage constraint, but lacks when-not-to-use or alternative recommendations.

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