rnw_tabs_select

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

With no annotations provided, the description carries the full behavioral burden but discloses almost nothing: it does not say what happens with an out-of-range index, whether the switch is synchronous, or what errors are returned. For a browser-control mutation of active focus, this is a meaningful gap.

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?

One short, front-loaded sentence with zero filler; the index semantics are not buried. It is appropriately sized for a single-parameter tool, though it is terse to the point of omitting useful context.

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 one-parameter tool with no output schema the description covers the core action, but it leaves the agent without failure-mode or sequencing guidance (e.g., obtaining valid indices), which is the minimum extra context this tool needs.

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% and the single parameter's schema already documents the 0-based indexing. The description merely repeats that fact, adding no syntax, range, or sourcing information beyond 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 ('Switch to') and resource ('browser tab') with the indexing scheme, which cleanly separates it from rnw_tabs_list, rnw_tabs_new, and rnw_tabs_close. It does not explicitly name those siblings, but the distinct action verb makes selection unambiguous.

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 only says what the tool does; it gives no when-to-use context, no prerequisites (e.g., that the tab index must come from rnw_tabs_list), and no alternatives. An agent must infer the usage entirely.

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