list_headless_windows

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering the safety profile. The description adds useful context about it being scoped to top-level windows on an off-screen desktop and details the return JSON shape (handle, process_id, thread_id, dpi, title, class, width, height). It doesn't contradict 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 compact with a one-line purpose statement followed by Args and Returns sections. It's front-loaded with the action and is efficient, though the Args section is redundant given the schema already documents the parameter.

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?

The output schema is present, so return-value documentation in the description is bonus context, not a requirement. Annotations cover safety and idempotency. The description adequately clarifies the tool is for off-screen desktop windows and lists the exact return fields, which disambiguates it from list_windows. For a simple 1-parameter read-only listing tool, this is reasonably complete.

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 carry the parameter meaning burden. It explains 'desktop name' as a single-line mention in Args, which maps to the HeadlessDesktopInput.name parameter. The description adds minimal value beyond schema—the schema itself describes name as 'Name of the off-screen desktop' with a default, which actually covers the semantics reasonably well.

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' with a specific verb+resource pair. It distinguishes itself from sibling list_windows (which likely lists on-screen) and list_child_windows (child, not top-level). However, it doesn't explicitly name alternatives for purposes of differentiation.

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 context—that it lists top-level windows on an off-screen desktop—but provides no explicit when-to-use vs when-not-to-use guidance or mention of alternatives. Sibling tools include list_windows and list_child_windows, but the description doesn't call out when to choose this one over those.

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