check_responsive

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

With no annotations to rely on, the description carries the burden of disclosing behavior. It explains that the tool takes screenshots at multiple widths, audits layout at each, and reports horizontal overflow, which is meaningful behavioral detail beyond the tool name.

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?

Two sentences with no filler. The core action is front-loaded, and the final sentence adds valuable domain knowledge about the most common responsive bug, making every word earn its place.

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 diagnostic tool with no annotations and no output schema, the description gives enough context to select and invoke it correctly: it explains the method, the purpose, and the key reported finding. It could be more explicit about prerequisites such as having a page open, but the default parameter values and schema descriptions cover invocation details.

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 coverage is 100% and every parameter has a helpful description, so the baseline is 3. The tool description adds only general context like 'several widths' but does not enrich parameter meaning beyond what the schema already 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?

States the specific behavior: screenshots the page at several widths and runs a layout audit per width, with a concrete output of horizontal overflow detection. This clearly distinguishes it from sibling tools like screenshot and audit_design by tying the check to responsive breakpoint diagnostics.

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 positions this as 'THE core design check' and explains the diagnostic outcome: seeing exactly which breakpoint breaks. It gives clear context for when to use it, though it does not explicitly name alternatives or state when not to use it.

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