List Monitors

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

Annotations already indicate read-only and non-destructive behavior. The description adds value by specifying the exact data returned (frame, visible frame, scale factor, main) and stating that no permission is required, which goes beyond the annotations. It doesn't cover edge cases, but the tool is simple.

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 a single sentence that starts with the verb 'List', immediately states the resource, and includes all relevant details without any wasted words. It is highly concise and well-structured.

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 zero parameters, present annotations, and no output schema, the description is complete enough. It specifies what is listed, the fields returned, and permission requirements. There is no ambiguity about the tool's behavior within its simple scope.

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 has zero parameters, so the schema is trivially complete (100% coverage). The description doesn't need to explain parameters, and with zero params, a baseline of 4 is appropriate per the rubric.

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 the tool's function: 'List connected displays' with specific attributes (frame, visible frame, backing scale factor, and which one is main). The verb 'List' and resource 'displays' are specific, and the attribute list distinguishes it from other listing tools.

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 provides clear context that it lists monitor information and notes that no permission is required. It doesn't explicitly mention alternatives, but there are no direct sibling tools for monitors, so usage is straightforward. The guidance is clear though not exhaustive.

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