system_list_windows

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

Annotations already establish that this is a safe, idempotent, non-destructive read. The description adds genuinely useful behavioral context beyond them: a prerequisite permission (Screen Recording) that gates whether window titles are populated on some macOS versions. It does not describe scope limitations such as only visible/minimized windows or ordering.

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 compact sentences with the core action front-loaded, followed by the permission caveat that directly affects output reliability. The bracketed version/permission tag is slightly noisy but carries real prerequisite information.

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?

An output schema exists, so return-shape details are not needed. For a zero-parameter read tool with rich annotations, the description covers purpose and the key permission prerequisite; only explicit routing to sibling tools is missing.

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 tool takes zero parameters, so the baseline is 4. The description correctly implies a no-argument listing operation and adds the permission-dependent behavior of the title field, which is meaningful even without parameters.

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?

States a specific verb and resource ('List visible window metadata'), which is clearly distinct from the single-window sibling system_get_active_window and from system_list_apps. It does not explicitly name a sibling to differentiate scope, but the 'list all windows' intent is unambiguous.

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 when-to-use or when-not-to-use guidance, and no routing to alternatives such as system_get_active_window for a single window or system_list_apps for applications. The only conditional context is a permission caveat, not a selection rule.

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