Playwright MCP Server

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

Annotations indicate this is a destructive, non-read-only operation with open-world hints, but the description adds valuable context: it specifies that typing targets 'editable element' and mentions behavioral options like submitting text or typing slowly to trigger key handlers. This goes beyond annotations by clarifying the interaction scope and optional behaviors, though it doesn't detail error cases or permissions.

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, front-loaded sentence that directly states the tool's purpose without unnecessary words. It efficiently conveys the core action and target, making it easy to parse and 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 (5 parameters, destructive hint, no output schema), the description is minimal but adequate. It covers the basic action but lacks details on error handling, return values, or integration with sibling tools like 'browser_snapshot'. With annotations providing safety context, it meets a minimum viable threshold but leaves gaps for a mutation tool.

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?

With 100% schema description coverage, all parameters are documented in the schema. The description adds no additional parameter semantics beyond what's in the schema (e.g., it doesn't explain 'element' vs. 'ref' distinctions or provide examples). The baseline score of 3 is appropriate as the schema carries the full burden of parameter documentation.

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 ('Type text') and target ('into editable element'), providing a specific verb+resource combination. However, it doesn't explicitly distinguish this tool from sibling tools like 'browser_fill_form' or 'browser_press_key', which might have overlapping functionality for text input scenarios.

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 like 'browser_fill_form' (for forms) or 'browser_press_key' (for keyboard input). It also doesn't mention prerequisites such as needing a page snapshot or element reference from 'browser_snapshot', leaving usage context implied rather than explicit.

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