live_open

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

With no annotations, the description carries the full burden and does reasonably well: it discloses that the viewer is local-only, that it returns a URL to open in the browser pane, that a `path` argument will open that specific file, and that user actions in the viewer produce review notes as a side effect. It stops short of stating whether the call blocks on user interaction, how to stop the viewer, or what happens on an invalid path.

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 identity and return behavior are front-loaded, which is good, but the middle passage is a laundry list of viewer features (onion skin, side-by-side/difference/blink compare, version diffs) that mostly describes the UI rather than how to invoke the tool. Several of those clauses could be trimmed without losing invocation-relevant 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 single-optional-parameter tool with no output schema, the description covers the essential contract: what it launches, that it is local, and that it returns a URL. Remaining gaps (URL form, failure modes, whether it blocks) are minor given the tool's narrow scope.

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 0%, so the description must supply the meaning of `path`, and it does at a basic level ('with `path` it opens that file'). It adds nothing about expected file type, relative vs. absolute paths, or behavior when omitted (the null default implies the default project), so it only partially compensates for the documentation gap.

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 identifies the tool as the built-in Studio Live web viewer and states that it returns a URL to open in the browser pane, which is a concrete resource and effect. It implicitly contrasts with siblings like view/compare by describing the viewer's interactive review features, though the opening sentence never uses an explicit verb like "opens" or "launches."

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?

It gives one concrete downstream workflow ('read those with review_notes') that routes the agent to a sibling, which is genuinely useful. However, it never explains when to choose live_open instead of the sibling `view`, `compare`, or `rig_preview`, nor any when-not conditions, so the selection logic against the closest alternatives is left to inference.

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