run_visual_test

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

No annotations are provided, so the description carries the full burden. It does add genuinely useful behavioral context – the external dependency on chrome-devtools-mcp and the viewport sweep – but says nothing about execution cost, timeouts, whether it is safe/non-destructive, or how results are surfaced.

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?

Front-loaded with the core action, followed by a tight bullet list of what is analyzed and a clear usage sentence plus prerequisite. The bullets each earn their place, though the list format is slightly heavier than needed for a three-parameter tool.

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?

With no output schema, the description should ideally hint at what comes back (screenshots, pass/fail, report artifact), but it stops at what is analyzed. The prerequisite and analysis breakdown cover the input side adequately, leaving the result side underspecified.

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 url, fullPage, and viewports are already documented in the schema. The description's mention of mobile/tablet/desktop viewports loosely reinforces the viewports parameter but adds no syntax or default semantics beyond what the schema states.

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?

States a specific verb ('Perform visual testing') and resource ('web application'), then enumerates the exact artifacts analyzed (screenshots, layout consistency, responsive design, alignment/spacing). The 'visual' scope implicitly separates it from the functional/performance/accessibility/SEO siblings, though it never names them explicitly.

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?

"Use this tool when you need to evaluate the visual appearance and responsiveness of a website" gives a clear usage context, and the prerequisite (chrome-devtools-mcp running) is stated. However, it offers no explicit exclusions or routing to siblings like run_full_test or run_accessibility_test.

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