browser_open_tab

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

With no annotations, the description carries the full load and delivers real behavioral facts: it does not wait for page load, a failed claim leaves the tab open, the tab identity is surfaced in error.open_tab, and creation must not be auto-retried. It omits what a successful call returns (handle vs id) and any auth/permission requirements, which keeps it short of 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?

Two tight sentences, front-loaded with the core behavior and then the claim semantics and failure caveat. Every clause carries information; the density is high but the ordering is sensible rather than wasteful.

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?

No output schema and no annotations mean the description is the only source of truth, and it does well on side effects and failure modes. It is still incomplete for a 4-parameter tool: 'active' is unexplained and the successful return value/handle semantics are never stated.

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% across 4 parameters, so the description must compensate and only covers one: 'claim'. It never explains 'active' (activation/foreground semantics), 'browser_id' (profile selection), or the URL format beyond HTTP(S). Three of four parameters remain semantically opaque.

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 concrete verb and resource ('Create a new HTTP(S) tab in the selected profile') and adds a distinguishing scope note ('even if the URL is already open'), which separates it from a plain navigate. It never names the sibling it replaces (browser_navigate, browser_claim_tab, browser_tab_control), so full differentiation still requires the sibling list.

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?

Guidance is implied through behavior: 'claim=true also acquires a tab_handle without tab discovery' implicitly points at browser_discover/browser_claim_tab as the alternative path, and 'never automatically repeat creation' constrains retry behavior. There is no explicit statement of when to prefer this over browser_navigate or browser_tab_control, so the agent must infer the routing.

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