browser_open_tab

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

Without annotations, the description carries the full burden: it discloses the critical '[Disabled]' state upfront, explains the return value (new tab ID) despite the absence of an output schema, and details the multi-profile selection logic. Minor gap regarding error handling or side effects prevents a 5.

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?

Four sentences with zero waste: status warning ([Disabled]), core action + return value, consumption guidance (sibling tools), and parameter logic. Information is front-loaded and logically ordered.

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 no output schema, the description compensates by detailing the return value. Given no annotations, it compensates by stating the disabled status. It also references relevant sibling tools for workflow context, making it complete for a 2-parameter 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?

With 100% schema description coverage, the baseline is 3. The description paraphrases the schema's connectionId logic (targeting profiles, arbitrary selection) and mentions 'specified URL', but does not add significant semantic depth beyond what the structured schema already provides.

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 clearly states the specific action ('Open a new browser tab'), the required input ('specified URL'), and distinguishes from sibling tools by explaining the returned tab ID is intended for use with browser_navigate_tab, browser_close_tab, and browser_execute_script.

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?

Provides explicit guidance on when to use the optional connectionId parameter ('When multiple browser profiles are connected'), references the prerequisite tool to obtain valid values ('get connectionIds from browser_list_tabs'), and clarifies the default behavior without the parameter ('opens in an arbitrary profile').

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