tab_new

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. While it mentions the basic action of creating a tab, it doesn't describe what happens after creation (e.g., does focus shift to the new tab?), whether there are permission requirements, rate limits, or error conditions. For a mutation tool with zero annotation coverage, this leaves significant behavioral gaps.

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 perfectly structured and concise. The first sentence states the core purpose, followed by a well-organized Args section with clear explanations for each parameter. Every sentence earns its place with no wasted words, and the information is front-loaded effectively.

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 that there's an output schema (which handles return values), 3 parameters with good semantic coverage in the description, and no annotations, the description is mostly complete. It explains what the tool does and how to use parameters effectively. The main gap is in behavioral transparency for a mutation tool, but the presence of an output schema reduces the need to describe return values.

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 description provides excellent parameter semantics in the Args section, explaining what each parameter does beyond the schema's basic titles. It clarifies that 'profile' is a name for the new tab, 'window_id' can be omitted for the current window, and 'command' runs in the new tab. With 0% schema description coverage, this fully compensates and adds meaningful context.

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 specific action ('Create a new tab') and resource ('in an iTerm2 window'), distinguishing it from sibling tools like tab_close, tab_list, or window_new. It provides a precise verb+resource combination that leaves no ambiguity about the tool's function.

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 provides clear context for when to use this tool (creating tabs in iTerm2) and includes usage guidance in the Args section (e.g., 'Omit for the current window'). However, it doesn't explicitly state when NOT to use it or name specific alternatives among the many sibling tools, which prevents a perfect score.

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