browser_tabs

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

Annotations already declare the tool non-read-only and destructive, and the description's 'close' action is consistent with that; there is no contradiction. The description adds no further behavioral context, such as that 'list' is read-only or what exactly gets destroyed when a tab is closed, so it does not go beyond the annotations.

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 with no filler. The operation list is presented immediately and matches the tool's scope, making it appropriately sized for a tool whose parameters are already documented in the schema.

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 four-action tool, the description is terse and relies heavily on the schema for action-specific requirements such as url for 'new' and index for 'close/select'. It also does not clarify what 'list' returns, but the schema and annotations cover most invocation details, making it minimally complete rather than richly descriptive.

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%, with clear explanations for all three parameters including the enum meanings and optional-index behavior. The description itself adds no extra parameter meaning beyond what the schema already provides, so 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?

The description uses specific verbs — list, create, close, select — tied to the 'browser tab' resource, so an agent can identify the tool's scope. It is slightly weaker on sibling differentiation because it never distinguishes tab closing from browser_close or tab navigation from browser_navigate, and it says 'create' while the action enum uses 'new'.

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?

Usage is implied by naming tab-level operations, but the description gives no explicit when-to-use or when-not-to-use guidance. With siblings like browser_navigate and browser_close available, the agent must infer that this tool handles tab-level actions while those handle navigation and window-level actions.

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