Set browser instance visibility

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

Annotations declare readOnlyHint=false, destructiveHint=false, idempotentHint=false and openWorldHint=false, so the safety profile is already covered. The description adds a useful non-obvious constraint (API-launched instances only, requires reveal/conceal options), but says nothing about what happens on an unsupported instance or whether the change persists across sessions.

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 short sentences with no filler; the purpose comes first and the eligibility constraint second. Every clause carries information the agent needs.

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?

With no output schema, the description need not explain returns, and all three parameters are covered by the schema. It supplies the key precondition for a niche operation, but leaves the failure mode for ineligible instances (error vs. silent no-op) unstated.

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 100%, with isVisible, profileId and workspaceId all documented inline, including the -1 default for workspaceId. The description's '(show or hide)' merely restates the boolean semantics already in the schema, so the baseline 3 applies.

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 ('Set') and resource ('browser instance window visibility') with an immediate gloss of the two states (show or hide). It is distinguishable from the nearest sibling, focus_browser_instance, though the description never explicitly contrasts them, so it stops short of a 5.

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 second sentence gives a real precondition for use — only instances launched via the API with reveal or conceal options are supported — which is genuine when-to-use guidance. However, it offers no routing against alternatives such as focus_browser_instance or start_browser_instance, and no explicit 'do not use for X' framing.

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