list_headless_windows

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

Annotations already declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, and destructiveHint=false. The description adds the return JSON structure (ok, name, count, windows with specific fields) and specifies 'top-level windows,' providing useful behavioral context beyond annotations. It doesn't describe error behavior, but for a read-only list tool this is acceptable.

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 concise and front-loaded with the main sentence, followed by a clear Args/Returns breakdown. Every sentence serves a purpose, and there is no unnecessary verbosity.

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 the tool's simplicity (one parameter, read-only, idempotent), the description is sufficiently complete. It includes the return format, acting as an informal output schema. Minor omissions like error handling or prerequisite desktop existence don't significantly impact usability.

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 describes the 'name' parameter as 'Name of the off-screen desktop.' The description redundantly states 'params (HeadlessDesktopInput): desktop name,' adding no new information. With schema description coverage reported as 0%, the description should compensate but does not clarify the default value, constraints, or how to discover available desktops.

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 'List the top-level windows living on an off-screen desktop,' specifying the action (list), resource (windows), and scope (off-screen desktop). It distinguishes itself from siblings like list_windows (likely for the regular desktop) and list_child_windows.

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 clear context that the tool is for headless desktops and requires a desktop name via params. It does not explicitly name alternatives or exclusions, but the context is unambiguous. Slight deduction for not mentioning when not to use it or comparing to list_virtual_display_windows.

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