browser_get_new_tab

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

With no annotations provided, the description carries the full burden of behavioral disclosure. 'Get' reasonably signals a non-destructive read, and the use-case context adds some value. However, it does not disclose the crucial behavioral detail of whether 'get' returns a tab reference for subsequent use or also activates/switches to the tab — a meaningful ambiguity given browser_switch_tab exists as a sibling.

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?

A single sentence with the core action front-loaded ('Get the most recently opened tab') and the use case appended as a tight parenthetical. Every word earns its place; there is no filler, repetition, or schema echo.

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 zero-parameter tool this is mostly adequate — it covers what the tool does and when to use it. But with no output schema and no annotations, the description is the sole source of the return contract, and it leaves unspecified whether the result is a tab ID, a tab handle, and whether the active tab changes. Some guidance relating it to browser_switch_tab or browser_list_tabs would close the gap.

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 tool has zero parameters, so the baseline is 4 — there is nothing the description needs to explain about inputs. The description adds useful context about what the returned entity represents (the most recently opened tab) and when the call is relevant, which is more than the empty input schema alone could convey.

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 states a specific verb and resource — 'Get the most recently opened tab' — and adds a concrete use case (links opening new tabs, OAuth popups). It is unambiguous about what is retrieved. However, it does not explicitly differentiate from closely related siblings like browser_switch_tab or browser_list_tabs, leaving the agent to infer the distinction.

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 parenthetical gives explicit usage context: 'useful after clicking links that open new tabs, OAuth popups, etc.' This tells the agent the trigger condition for choosing this tool. It stops short of naming alternatives or exclusions, such as pointing to browser_switch_tab for already-known tabs or browser_list_tabs for enumerating tabs, so it lacks the when-not guidance of a 5.

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