vroid_open_tab

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

With no annotations provided, the description carries the full burden. It discloses the ~2 second wait for redraw, the return of a verification screenshot path, and the suggestion to take a screenshot to view results. It does not specify failure modes (e.g., what happens if OCR cannot find the tab), but the disclosed timing and return behavior are useful. No contradictions with annotations (since none exist).

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 very concise, with the core purpose in the first sentence and supporting details in a short second paragraph. It front-loads the function and then adds necessary constraints and behavior without any redundant or irrelevant content. Every sentence adds value.

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?

Given the availability of an output schema (though not shown) and high parameter schema coverage, the description provides sufficient context for an agent to call the tool correctly. It covers the environment limitation, the wait time, and the return value. Missing details include error handling when OCR fails, but for a tool that is part of a larger suite with similar patterns, this is a minor gap.

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?

The schema description covers 100% of the single parameter 'name' with clear allowed values (Face, Hairstyle, Body, Outfit, Accessories, Look). The description does not add additional meaning about the parameter beyond what the schema already provides, which is acceptable given the high schema coverage. The baseline 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 verb ('Switch'), a clear resource ('top-level tab'), and the method ('located by OCR of the tab strip'). It clearly distinguishes this from sibling tools like vroid_click (which clicks generic elements) or vroid_find_text (which locates text), since it is specialized for tab switching. The screen restriction further refines its purpose.

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 states the tool only works on the editor screen, excluding start, export, and hair editor screens, which tells the agent when not to use it. However, it does not directly mention alternatives or contrast with sibling tools like vroid_click when a tab is already visible. The guidance is clear on the environment constraint but lacks explicit 'use this instead of X' phrasing.

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