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

Annotations already declare destructiveHint=true and idempotentHint=true; the description adds real value by spelling out what is destroyed/overwritten — the prior baseline is replaced by the current screenshot — and by pointing to the undo path. It stops short of stating permission requirements or what happens to the superseded baseline snapshot.

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?

Three tight sentences, front-loaded with the action and effect, with the precondition and undo hint following. Slight verbosity in the parenthetical 'a redesign, new content' but it usefully exemplifies intent.

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 single-parameter mutation with no output schema and annotations covering the safety profile, the description supplies the essential missing pieces: what changes, when to use it, and how to reverse it. Minor gaps (auth/permissions, scope of baseline replacement) remain but are not critical.

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?

Single parameter with 100% schema description coverage, so the schema already explains comparisonId's origin (get_run visualComparisons[].comparisonId). The description adds no parameter-level detail, which is acceptable at this coverage level.

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+resource ('accept a visual change') and immediately clarifies the effect: this run's screenshot becomes the new baseline for that page/device/browser. Sibling tools like undo_visual_review, ignore_visual_change, and flag_visual_change_as_problem are clearly distinct from this acceptance action.

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 an explicit precondition ('Only when the user confirms the change is intended') and names the reversal tool ('Undo with undo_visual_review'). It does not explicitly contrast with ignore_visual_change or flag_visual_change_as_problem, but the intended-vs-unintended framing covers the key branch.

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