New tab

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

No annotations are provided, so the description carries the full disclosure burden. It usefully states that the call returns the tab ID and warns about cross-agent tab mixing, but says nothing about whether the new tab becomes the active/focused tab, its interaction with the slot's current state, or any permission requirements. Some behavioral value added, clear gaps remain.

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, zero filler. The core action and return value are front-loaded, and the multi-agent caution follows as supporting 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?

With no output schema, the description helpfully notes the returned ID, and the 100% schema coverage handles parameter detail. It is nearly complete for a small connector tool, only missing behavioral detail such as whether the new tab takes focus.

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%, so all four parameters (url, slot, agent, summary) are already richly documented, including slot parsing rules and the agent display-name default. The description adds no format or meaning beyond the schema. Baseline 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?

States a specific verb and resource ('Opens a new tab in the slot') and adds the useful side effect that it returns the tab's ID. It is naturally distinguishable from browser_tabs, browser_tab_close, and browser_tab_select by operation, though it never names those siblings explicitly.

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 clear context for use: 'When agents share a slot, open your own tab and work only by its ID to avoid mixing.' This tells the agent a concrete scenario and the behavioral convention to follow. However, it gives no exclusions or explicit alternatives (e.g. when to re-use an existing tab instead of opening a new one).

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