Run Playwright E2E tests

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

With no annotations, the description must carry behavioral disclosure. It transparently states that it starts a dev server if configured and returns structured results, which is the core behavior. However, it does not disclose potential side effects such as file modifications, server teardown, or environmental requirements like locally installed Playwright, leaving some transparency gaps.

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, well-structured sentence that front-loads the main action and then details the conditional server startup and output format. There is no redundancy or unnecessary detail.

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 test runner with five parameters, the description covers the overall flow and return format sufficiently. The schema handles parameter details, and the description clarifies the conditional server startup. It lacks some environmental prerequisites, but overall it is adequate for an agent to call it correctly.

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?

Because the input schema already provides descriptions for all five parameters, the baseline is 3. The description adds a little context by linking the dev server startup to the Playwright config, but it does not add new parameter-specific semantics beyond what the schema provides.

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 explicitly states the tool runs Playwright tests and returns structured pass/fail results, with a clear verb and resource. It also mentions spinning up a dev server, which helps distinguish it from siblings like typecheck or npm_run.

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 implies its usage by identifying Playwright E2E testing as the core function. However, it does not explicitly name alternatives or specify when not to use it, leaving some room for interpretation. The context is clear enough that an agent would know to use it for running E2E tests.

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