tabs_create_mcp

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

No annotations are provided, so the description must carry the full burden of behavioral disclosure. It states that a new empty tab is created but does not disclose whether the tab becomes active/focused, what the return value contains (though an output schema exists), or any side effects. This is a significant gap for a browser automation tool.

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 front-loaded sentence that says exactly what the tool does in 10 words. There is no redundancy or unnecessary detail; every word contributes to the meaning.

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?

The tool is simple (no params, output schema exists), but the description omits important behavioral context such as tab activation or focus behavior. It is minimally sufficient for an agent to invoke the tool, but not fully complete for understanding the post-conditions of that invocation.

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 parameter semantics are trivially satisfied. Per the rubric, a zero-parameter tool gets a baseline score of 4. The schema also reflects this with an empty properties object, so the description need not add parameter details.

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 ('Creates') and identifies a clear resource ('a new empty tab') and location ('in the MCP tab group'). This clearly distinguishes it from sibling tools like tabs_context_mcp (context) and tab_control (manipulating existing tabs).

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 description does not provide any guidance on when to use this tool versus alternatives such as navigate or tab_control. It simply states what the tool does, leaving the agent to infer usage from sibling tool names. No exclusions, prerequisites, or alternative recommendations are given.

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