create_window

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

Annotations already declare readOnlyHint=false and idempotentHint=false, indicating a mutating, non-idempotent operation. The description adds the target session scoping constraint, which is useful context. However, it doesn't disclose side effects such as the new window being selected by default (select parameter defaults to true), so it doesn't fully go beyond annotations.

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 a single, front-loaded sentence with no filler words. It is concise and well-structured, containing only the essential information (action, object, scope).

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 4 optional parameters and an output schema, the description is too sparse. It doesn't inform the agent about implications of 'select' (defaulting to true, meaning the new window becomes active) or 'start_directory'. This is a significant gap for a tool that can affect session state, making the description incomplete for reliable invocation.

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, but it only clarifies the 'target' parameter via 'in target session'. It does not explain 'name', 'select', or 'start_directory' meanings, leaving most parameters semantically under-specified.

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 uses a specific verb ('create') and resource ('new window') with a target scope ('in target session'), clearly distinguishing it from sibling tools like list_windows or create_session. It explains what the tool does without ambiguity.

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 usage for creating a window in an existing session, but it does not explicitly mention when not to use it or provide alternatives. Sibling tool names like create_session and split_pane exist, but no exclusion or comparison is given, leaving guidance at an implied level.

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