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

Annotations already establish that this tool is read-only, idempotent, and non-destructive. The description adds value by disclosing what kind of information the tool exposes (monitor bounds, scale, primary display), which helps the agent predict the result. It does not contradict the 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?

A single, front-loaded sentence conveys the tool's purpose and usage context with no filler. Every clause earns its place, and the scoping condition is stated before any technical details.

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 simple read-only query tool with one documented parameter, an output schema, and clear annotations, the description is complete. An agent has enough information to know when to call it and what to expect from it.

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 input schema provides 100% coverage for the single device parameter, including its meaning and source (ReMCP device id from list_devices). The description adds no parameter-specific detail beyond the schema, so the baseline of 3 is appropriate.

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 identifies what the tool provides: monitor bounds, scale, and primary-display information, and ties it to monitor-specific screenshots and cross-monitor coordinate work. It is distinct from sibling screenshot tools because it supplies display geometry rather than capturing images, though it stops short of an explicit 'returns a list of displays' statement.

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 gives explicit conditions for use: monitor-specific screenshots, cross-monitor geometry, or coordinate work requiring monitor bounds, scale, and primary-display info. It does not name alternative tools or state when not to use it, but the guidance is specific enough to route an agent effectively.

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