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

Annotations already declare readOnly/idempotent/non-destructive, so the description's added value is the auth and approval requirement: account-bound computer:write OAuth plus any prompted local owner approval — a non-obvious constraint for a read operation. It does not specify how large the 'bounded' list is or what happens if approval is denied, which keeps it short of a 5.

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?

Three clauses, each carrying distinct information: what is returned, the sibling alternative, and the permission requirement. The output-scope statement is front-loaded and nothing is redundant with the title or annotations.

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 input schema and no output schema, the description carries the whole burden and mostly does: it defines the returned content (names only, no pixels), bounds it, and discloses the auth path. The remaining gap is that the size and ordering of the 'bounded list' are never stated.

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 there is nothing for the description to disambiguate and the baseline of 4 applies. It correctly avoids inventing filtering options that the empty schema does not support.

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 gives a specific verb (get a bounded list) plus a precisely scoped resource (currently visible window names), and explicitly contrasts that with exza_list_desktop_apps for installed apps. An agent can distinguish this from its many list_* 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?

It names the alternative tool and the condition that selects it (enumerate installed apps), and rules out a plausible but wrong expectation by stating no screenshot or window pixels are returned. Both the when-to-use and the when-not are covered explicitly.

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