Playwright MCP Server

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

No annotations are provided, so the description carries full burden. It states the action but lacks behavioral details: it doesn't mention if this requires the page to be in a specific state, what happens on failure (e.g., if selector not found), whether it waits for elements, or any side effects like page navigation. 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 with zero waste. It's front-loaded and appropriately sized for the tool's complexity, making it easy to parse quickly.

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 this is a mutation tool with no annotations, no output schema, and incomplete behavioral disclosure, the description is insufficient. It should cover more about how the tool behaves, error conditions, or what it returns, especially since it interacts with web elements and has potential side effects.

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 both parameters (selector and value) adequately. The description adds no additional meaning beyond implying 'Select tag' context, which doesn't clarify parameter usage beyond what the schema provides. Baseline 3 is appropriate when 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 action ('Select') and target resource ('element on the page with Select tag'), making the purpose immediately understandable. It distinguishes from siblings like playwright_click or playwright_fill by specifying it's for Select elements, though it doesn't explicitly contrast with all similar tools.

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?

No guidance is provided on when to use this tool versus alternatives. While 'Select tag' implies it's for dropdown/select elements, it doesn't specify prerequisites (e.g., page must be loaded), exclusions, or direct comparisons to other playwright tools for similar interactions.

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