mcp-electron-driver

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It adds value by specifying 'Fast check' (implying low latency), 'Does not wait' (clarifying non-blocking behavior), and that it returns 'the count' (output detail). However, it doesn't cover aspects like error handling, performance limits, or what 'matches' entails (e.g., partial vs. exact), leaving gaps for a tool with potential UI interactions.

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 highly concise and well-structured: three short sentences that efficiently convey purpose, parameters, and a key behavioral trait ('Does not wait'). Every sentence adds value without redundancy, making it easy to parse and front-loaded with essential information.

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 moderate complexity (2 parameters, no output schema, no annotations), the description is partially complete. It covers the core purpose and a behavioral trait but lacks details on output format (beyond 'count'), error cases, or integration with siblings like 'snapshot' for 'ref'. For a UI testing tool, this leaves room for improvement in guiding effective use.

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 description adds some meaning beyond the input schema: it explains that parameters are alternatives ('Pass `selector` or `ref`'), which isn't clear from the schema alone. However, with 50% schema description coverage (only 'ref' has a description), it doesn't fully compensate for the undocumented 'selector' parameter. The baseline is 3 since the schema provides partial coverage, and the description offers limited additional context.

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: 'Fast check for whether any element matches, plus the count.' It specifies the verb ('check'), resource ('element'), and outcome ('matches, plus the count'). However, it doesn't explicitly differentiate from siblings like 'check', 'wait_for_selector', or 'elements_list', which might offer similar functionality.

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 some implied usage guidance: 'Pass `selector` or `ref`' indicates parameter options, and 'Does not wait' suggests it's for immediate checks rather than waiting for conditions. However, it lacks explicit when-to-use vs. alternatives (e.g., compared to 'wait_for_selector' for delayed checks or 'elements_list' for listing elements), and no exclusions or prerequisites are mentioned.

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