session_split

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

No annotations are provided, so the description carries full burden. It states the action ('Split') but lacks behavioral details: it doesn't specify if this requires specific permissions, what happens to the original session, whether the split is reversible, or any rate limits. The description is minimal beyond the basic action.

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 front-loaded with the core purpose in the first sentence, followed by a structured Args section. Every sentence earns its place by explaining parameters without redundancy, making it efficient and well-organized.

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 3 parameters with 0% schema coverage and no annotations, the description adequately covers parameter semantics but lacks behavioral context (e.g., effects, permissions). An output schema exists, so return values need not be explained. However, for a mutation tool with no annotations, more behavioral disclosure would improve completeness.

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 description coverage is 0%, so the description must compensate. It provides clear semantics for all three parameters: explains what 'vertical' controls (orientation), 'session_id' target (with omission rule), and 'profile' usage (for the new pane). This adds meaningful context beyond the schema's titles and types.

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 ('Split an iTerm2 session into a new pane') with the resource ('iTerm2 session') and outcome ('new pane'). It distinguishes from sibling tools like session_close, session_focus, or tab_new by specifying the pane-splitting functionality.

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 guidance is provided on when to use this tool versus alternatives. The description does not mention prerequisites (e.g., requires an active session), exclusions, or comparisons to similar tools like tab_new or window_new for creating new interfaces.

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