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 effectively describes the tool's behavior: setting files without triggering the native file picker, requiring absolute file paths, and being designed for Electron testing. It doesn't mention error handling, permissions needed, or what happens if files don't exist, but covers the core behavioral traits well given the lack of 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?

The description is perfectly concise with three sentences that each earn their place: first states the core functionality, second provides critical context about Electron testing and comparison to alternatives, third gives parameter guidance. No wasted words, 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?

For a 3-parameter tool with no annotations and no output schema, the description provides good contextual completeness. It covers the tool's purpose, when to use it, behavioral characteristics, and parameter guidance. The main gap is lack of information about return values or error conditions, but given the testing context and parameter clarity, it's reasonably 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?

Schema description coverage is 67% (2 of 3 parameters have descriptions). The description adds valuable context beyond the schema: it clarifies that 'files' should be 'one or more absolute file paths' (reinforcing the schema's description) and implies the tool works on file input elements (context for 'selector'). While it doesn't detail 'timeoutMs' or 'selector' specifics, it compensates adequately for the partial schema coverage.

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 specific action ('Set files on an <input type="file">') and resource (file input element), distinguishing it from sibling tools like 'drop_file' by emphasizing it's the 'CORRECT way to test file upload UI in Electron' and 'more reliable than drop_file'. This provides explicit differentiation.

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 explicitly states when to use this tool ('the CORRECT way to test file upload UI in Electron') and when not to use alternatives ('much more reliable than drop_file'). It provides clear context for usage in Electron testing scenarios with file uploads.

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