GNOME Desktop MCP

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

With no annotations provided, the description carries the full burden. It mentions the action but doesn't disclose behavioral traits such as whether this requires focus on a specific window, if it's reversible, or what happens if coordinates are out of bounds. More context is needed for a mutation 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?

The description is a single, efficient sentence with no wasted words. It's front-loaded and directly states the tool's action, making it easy to understand at a glance.

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 the tool's complexity (a mutation with 3 parameters) and no annotations, the description is minimal. It states the action but lacks details on parameters, usage context, or behavioral effects. With an output schema present, return values are covered, but overall completeness is limited.

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?

Schema description coverage is 0%, so the description must compensate, but it adds no parameter information. The description doesn't explain what x, y, or button represent, leaving parameters undocumented. Baseline is 3 since schema coverage is low but description fails to add value.

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 action ('Press mouse button down') and specifies 'without releasing', which distinguishes it from a full click. However, it doesn't explicitly differentiate from sibling tools like 'mouse_click' or 'mouse_up' beyond the implied difference in action completion.

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?

No explicit guidance on when to use this tool versus alternatives like 'mouse_click' or 'mouse_up' is provided. The description implies it's for initiating a mouse press, but lacks context on typical use cases or prerequisites.

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