windows

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

Annotations already declare readOnlyHint=true, so the safety profile is known. The description adds the data source 'from accessibility', implying reliance on the OS accessibility tree rather than screen capture, which is useful context. However, it doesn't disclose potential failure modes, permission requirements, or the semantics of 'active' and 'ref' fields, so transparency is basic.

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?

One short sentence with no filler, front-loaded with the verb 'List' and immediately specifying the resource and fields. Every word earns its place.

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?

For a low-complexity tool with one optional boolean parameter and no output schema, the description covers the essential context: it lists windows, enumerates the returned fields, and notes the accessibility source. It doesn't explain field meanings or failure cases, but is largely adequate for correct 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?

The schema already fully describes the only parameter (positions) with meaning and a performance note ('slower'), and description coverage is 100%. The tool description adds no additional parameter semantics, so it relies on the schema – baseline 3.

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 the specific verb 'List' and resource 'open windows', and specifies the output fields (app, title, active, ref). The qualifier 'from accessibility' clearly separates it from visual screen-reading siblings like read_screen and ocr, so an agent can distinguish it without opening schemas.

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 gives no guidance on when to use this tool versus alternatives such as open_app, read_screen, or find. There are no when-not-to-use conditions or references to sibling tools, leaving the agent to infer applicability from the action alone.

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