browser_new_tab

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

With no annotations, the description fully bears the burden of behavioral disclosure. It only states the basic action ('Open a new browser tab') without mentioning side effects (e.g., whether focus switches to the new tab, error handling for invalid URLs, or return values). This leaves significant behavioral ambiguity.

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 a single sentence with no wasted words. It is front-loaded with the primary action and includes the key optional parameter. Extremely concise and well-structured.

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 the simplicity of the tool (one optional parameter, no output schema, no nested objects) the description is minimally adequate. However, it lacks context about what happens after opening (e.g., tab focus, behavior when no URL) and does not reference sibling tools or common usage patterns. A 3 reflects sufficiency for a basic tool but with gaps.

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 100% (one parameter, url, with default 'about:blank'). The description adds the word 'optionally' which reinforces the parameter's optionality, but otherwise adds little meaning beyond the schema. Baseline of 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?

The description uses a specific verb ('Open a new browser tab') and resource, clearly distinguishing it from sibling tools like browser_navigate (which navigates the current tab) and browser_tabs (which lists tabs). The optional URL parameter is mentioned, making the purpose unambiguous.

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?

No guidance is provided on when to use this tool versus alternatives (e.g., browser_navigate). There is no explicit context for when opening a new tab is preferred over navigating the current tab, nor any exclusions or prerequisites.

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