a11y-toolkit: Staging vs production diff

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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint false, so the safety profile is covered. The description adds meaningful context beyond that by noting the local Playwright dependency and clarifying that this is a convenience wrapper around two separate operations rather than a novel behavior.

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 two sentences with no filler. The core operation is front-loaded, and the manual alternative is included without 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 simple two-parameter, read-only tool with rich annotations, the description covers what the tool does, its prerequisite, and its relationship to the manual flow. No critical information needed to call it correctly is missing.

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 the parameter descriptions already explain that url_a is usually staging and url_b is usually production. The tool description adds no additional parameter-level meaning, so the baseline score of 3 is appropriate.

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 states a specific action: 'Snapshot two URLs and diff them in a single call,' with the staging-vs-production example making the resource and intent clear. It also distinguishes itself from the manual 'snapshot + a11y_diff' flow, so an agent can differentiate it from related sibling 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?

The description explicitly positions this tool as a convenience for staging-vs-production comparisons and names the manual alternative: 'snapshot + a11y_diff.' It also flags the prerequisite 'Requires local Playwright,' giving the agent concrete conditions for when this tool is appropriate.

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