MCP-Midscene

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It states the tool 'locates and clicks' an element, implying a mutation action (clicking changes page state), but doesn't disclose potential side effects (e.g., navigation, form submission), error handling (e.g., if element not found), or performance aspects (e.g., timeouts). This is a significant gap for a mutation tool with zero annotation coverage.

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: 'Locates and clicks an element on the current page based on a natural language description (selector).' It is front-loaded with the core action and includes essential details without waste. Every word earns its place, making it 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 the tool's complexity (a mutation action on a web page), lack of annotations, and no output schema, the description is incomplete. It doesn't cover behavioral traits like error conditions, side effects, or return values. While the schema covers the parameter well, the overall context for safe and effective use is insufficient, especially compared to siblings that might have overlapping functionalities.

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 has 100% description coverage, with one parameter 'locate' described as 'Use natural language describe the element to click.' The description adds minimal value beyond this, reiterating 'natural language description (selector)' but not providing examples, formatting tips, or constraints. With high schema coverage, the baseline score of 3 is appropriate as the schema does the heavy lifting.

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 purpose: 'Locates and clicks an element on the current page based on a natural language description (selector).' It specifies the verb ('locates and clicks'), resource ('element on the current page'), and method ('natural language description'). However, it doesn't explicitly differentiate from sibling tools like 'midscene_aiHover' or 'midscene_aiInput', which likely perform similar element interactions but with different actions.

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. It doesn't mention prerequisites (e.g., requires an active page or tab), exclusions (e.g., not for non-clickable elements), or comparisons to siblings like 'midscene_aiHover' for hovering or 'midscene_aiInput' for text input. Usage is implied by the action 'clicks,' but no explicit context is given.

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