mcp-electron-driver

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

With no annotations provided, the description carries full burden and discloses important behavioral traits: it wipes the screenshots directory on fresh start, detects single-instance-lock failure mode, and gives helpful hints. It doesn't cover all potential behaviors like error handling or performance characteristics, but provides substantial operational context.

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?

Four sentences with zero waste - each adds value: establishes purpose, prerequisite usage, parameter guidance, and behavioral details. Could be slightly more front-loaded by moving the 'Must be called before' clause earlier, but overall efficient.

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 complex initialization tool with 7 parameters, no annotations, and no output schema, the description provides good context about prerequisites, behavioral side-effects, and failure modes. It doesn't explain return values or what constitutes successful launch, but covers most critical operational aspects.

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 100%, so the schema already documents all 7 parameters thoroughly. The description mentions the 'main' parameter requirement and screenshotsDir behavior, but doesn't add significant semantic value beyond what's in the schema. Baseline 3 is appropriate when schema does 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 specific action ('Launch an Electron app via Playwright') and resource ('Electron app'), distinguishing it from sibling tools like 'stop_app' or 'accessibility_snapshot'. It specifies this is an initialization tool that must be called before other driving tools, establishing its unique role.

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?

Explicitly states 'Must be called before any other driving tool', providing clear when-to-use guidance. It also distinguishes from alternatives by mentioning this is for starting the app, unlike 'stop_app' or other interaction tools in the sibling list, though it doesn't name specific alternatives.

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