List Tabs (Plus)

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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior. The description adds valuable behavioral context: tab IDs are stable for the lifetime of the browser connection, eliminating the need to re-list repeatedly. It also specifies the return format, adding beyond the annotation-only safety profile.

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 well-structured and front-loaded with the core purpose, followed by a comparison to the base tool, a brief return format, and clear examples. Every sentence earns its place without redundant fluff.

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 zero parameters and the return format explicitly shown in the Returns block, the description provides everything needed to invoke and interpret the tool. It also addresses the stable-ID lifetime context, making it complete for this simple list operation.

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, and the schema is empty (100% coverage by default). The description explicitly states 'Args: none,' confirming the lack of inputs. With no parameters to explain, a baseline of 4 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 states exactly what the tool does: 'Lists every open tab with a stable tabId usable by every other tool in this server.' It uses a specific verb ('lists') and resource ('every open tab'), and clearly distinguishes its purpose from the base list-tabs and interaction siblings.

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 provides explicit usage guidance: 'Use when: you need to address a specific tab by id' and 'Don't use when: you already have a tabId from a previous call.' It also names the base connector alternative and clarifies when this tool is needed.

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