List Open Windows

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

No annotations are supplied, so the description carries the full burden. It usefully defines scope ('visible top-level windows') and the returned fields, but is silent on ordering, whether minimized/child/elevated windows appear, and any permission requirements.

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?

Two tight sentences: the core behavior and return fields come first, the usage hint second. No redundant restatement of the name or title, and nothing padded.

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 no output schema, the description compensates by naming the returned fields, and it covers the use case and scope. Remaining gaps (result ordering, edge-case window states) are minor for a simple read-only enumerator.

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 100%, so the single 'filter' parameter (case-insensitive substring on title, max 200 chars) is already fully documented. The description adds nothing about filtering, so the baseline 3 applies.

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?

Specific verb (List) + resource (visible top-level windows) plus the exact fields returned (handle, title, process id) and the scope qualifier 'visible top-level'. An agent can distinguish this enumeration tool from the screenshot/OCR-oriented siblings without opening any schema.

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?

Gives a concrete usage context: 'orienting yourself before deciding what to screenshot', which implicitly routes the agent to this tool ahead of the screenshot family. It does not explicitly name a sibling or state when not to use it, so it stops short of the top band.

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