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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=true and destructiveHint=false, so the safety profile is covered. The description adds genuine context beyond that: the capture happens in Better Design's own browser at three fixed widths, and the output is a deployment-tied receipt reporting specific fault categories. It stops short of mentioning auth requirements or failure behavior, so not a 5.

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 dense sentences with no filler; the capture-and-compare action is front-loaded and the return content follows. Slightly long and jargon-heavy ('Better Design's own browser'), but every sentence carries information.

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 complex tool with 7 params (6 required) and nested objects, and no output schema, the description carries the return-value burden well by explaining what the receipt reports. It is not fully complete: it omits required-input meaning, prerequisites, and how the comparison inputs relate to one another.

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 71%, so the baseline is around 3. The description maps conceptually to several inputs (submitted source, data, components, the public HTTPS URL), but it does not explain screen, knownTerms, or the required shape/constraints of fixture and componentSources beyond what the schema already 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?

The description names specific verbs (captures, compares, returns) and a concrete resource (deployed dashboard) with notable scope detail (390/1440/1728 px widths). It clearly conveys what the tool does, but it never distinguishes itself from the similarly named sibling review-dashboard-structure, so an agent cannot easily tell the two apart from text alone.

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?

There is no explicit when-to-use, when-not-to-use, or alternative-selection guidance. The description implies it is a final verification step ('finalize'), but it never states prerequisites, ordering, or how it differs from review-dashboard-structure.

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