Get display info

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds value by specifying the exact data returned and the coordinate system (Cocoa points), which is useful behavioral context. It does not contradict annotations and does not introduce any unknown side effects. A small deduction for not mentioning error behavior or permissions, but this is minor for a simple read-only listing.

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, well-structured sentence. The action and resource are front-loaded, and the list of returned fields follows naturally without excess words. Every part contributes to comprehension.

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?

For a read-only tool with no parameters and no output schema, the description is complete. It tells the agent exactly what the tool does and what data it returns. There is no ambiguity about the scope or the result format, as 'List' implies an array and the fields are enumerated. The inclusion of 'in Cocoa points' clarifies the coordinate frame, preventing misinterpretation.

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, and the schema coverage is 100% (empty schema). With no parameters to document, the description bears no burden here. Baseline of 4 applies.

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 verb 'List' and the resource 'attached displays', and enumerates the specific attributes returned (name, main flag, scale factor, frame in Cocoa points). This makes it unambiguous and distinct from sibling tools like get_system_info or list_applications, which cover broader or different domains.

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 no guidance on when to use this tool versus alternatives. There is no mention of alternatives, exclusions, or conditions. While the purpose is clear, an agent is given no help in deciding between this and other system-inspection tools, such as get_system_info.

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