switchTab

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

With no annotations provided, the description itself discloses a key behavioral trait: after switching, subsequent commands target the new active tab. This goes beyond the basic definition and helps an agent understand the stateful impact. It also implies a precondition (listTabs) but does not specify error behavior for invalid indices or unmatched patterns, so it is informative but not exhaustive.

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 three short sentences with no filler. The action is stated first, followed by the behavioral consequence and a helpful prerequisite, making every sentence valuable and easy to parse.

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 tool with no output schema, the description covers purpose, prerequisite, and statefulness. It lacks error-handling details, but given the low complexity and presence of a concrete usage hint, it is contextually sufficient. The absence of an output schema means return values are not specified, but that is not a significant gap for an action-oriented tool.

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 already provides complete information: the 'tab' parameter accepts either a 0-based index or a URL pattern with partial match. The description merely says 'by index or URL pattern' without adding details like partial matching, so it does not add meaning beyond the schema. Since schema coverage is 100%, the baseline of 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?

The description opens with a specific verb and resource: 'Switch active browser tab by index or URL pattern.' This clearly distinguishes it from sibling tools like listTabs (listing) and navigateTo (navigating to a URL), making the tool's purpose unmistakable.

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 instruction 'Use listTabs first to see available tabs' provides an explicit prerequisite, and 'all subsequent commands will target the new active tab' clarifies the operational context. While it names no alternative tools, the context is clear and sufficient for an agent to know when to invoke it vs. others.

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