Manage Tabs

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

The annotations already signal mutation and destructiveness (readOnlyHint=false, destructiveHint=true), and the description adds valuable behavioral detail: closing a page 'invalidates its refs and its delta read tokens,' and the result announces this instead of leaving a later failure. It also reveals the cookie-jar context behavior, going beyond the structured annotation hints.

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 dense but each sentence earns its place: the action list, the handle mechanism, the invalidation consequence, and the cookie-jar context. It is front-loaded with what the tool does, though the later sentences are somewhat intricate for the available parameter detail.

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?

This is a multi-operation, destructive tool with five parameters, no output schema, and no enum constraints, yet the description leaves the parameter model largely implicit. It does not explain the allowed `action` values or how to request 'report which is focused' or 'capture pages a click opened in a popup,' so an agent cannot reliably construct a correct call from the definition alone.

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 0%, so the description must compensate, but it only meaningfully explains `context`. The description implies action-related behaviors and page/session concepts, but it never maps parameters like `action`, `url`, `page`, or `session` to concrete values or usage, leaving the agent to guess how to invoke each operation.

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 opens with a specific verb list and resource: 'List, open, select, or close tabs, report which is focused, and capture pages a click opened in a popup.' It also states the tool's unique role by explaining it mints 'explicit page handles every other tool accepts,' which distinguishes it from the sibling tools that consume those handles.

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?

It clearly conveys when to use the tool: to manage tabs and, importantly, to obtain the page handles that other tools depend on for state across calls. It does not explicitly name alternatives or give when-not-to-use guidance, so it stops short of a 5.

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