List Displays

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

With no annotations, the description carries the full disclosure burden. It reveals the return payload shape (id, name, primary flag), which is genuine added value, but says nothing about whether the display list can change at runtime, whether enumeration requires any permission, or how refreshes are handled. Adequate for a trivial read, but incomplete for a zero-annotation tool.

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?

Two sentences, no filler, with the resource and return fields front-loaded and the follow-up instruction second. Every clause earns its place.

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?

There is no output schema, so the description must describe returns — it does so at a field level (id, name, primary flag), which is sufficient for a simple enumeration call. Only the absence of any note about dynamic display changes or permissions keeps it from being fully 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?

The tool takes no parameters, so per the baseline a 4 applies. The description correctly adds no per-argument detail because there are none to document.

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?

Specific verb (List) plus resource (connected displays) with the returned fields enumerated (id, name, primary flag). It is immediately distinguishable from siblings like list_windows or screenshot, which deal with windows or pixels rather than display enumeration.

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?

Explicitly states the downstream use case: take the returned id and pass it to `screenshot` or `screenshot_region` to target a monitor. That names the alternatives and the condition that selects them, but there is no guidance on when this call is unnecessary (e.g., single-monitor setups) or any prerequisites.

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