a11y_reflow

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

With no annotations, the description carries the burden and does well: it discloses the measurement procedure (load at 1280px, then 320px), what is returned (real horizontal scroll and the overflowing elements), and a hard prerequisite ('Requires local Playwright'). It omits auth/network/rate-limit traits and does not restate that the operation is non-mutating, but the operational profile is largely conveyed.

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 purpose and criterion before the method detail, and every sentence carries information (scope, output, prerequisite). The parenthetical method note about zoom re-layout is defensible justification but lengthens the definition more than strictly needed.

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?

No output schema or annotations exist, so the description is the only source of behavior — it covers procedure, output shape and environment requirement well. However, two of three parameters (lang, timeout) are left entirely unexplained, leaving the agent unable to populate them confidently.

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 0% across 3 parameters, so the description must compensate, and it does not: only 'url' is implicitly explained ('Loads the URL'). The 'lang' enum and 'timeout' parameters are completely undocumented in both schema and description.

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 check ('Reflow check at 320px') tied to a named WCAG criterion (1.4.10 AA), which cleanly separates it from the generic a11y_audit_url sibling. It also explicitly claims the niche of checks 'axe and Lighthouse do not automate', so an agent can place it without opening the schema.

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?

Gives a clear context for use: this is the tool for 1.4.10 reflow verification that automated scanners miss. It does not name a sibling alternative or state when-not-to-use, so it stops short of full routing guidance.

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