browser_set_storage_state

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

The description explicitly states the key behavioral side effect: 'This clears existing cookies and local storage before restoring.' This adds critical context beyond the { destructiveHint: true } annotation, which only indicates potential destructiveness without detailing what exactly gets cleared. The agent is thus well-informed about the tool's impact on the browser state.

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 consists of two short, clear sentences. The first sentence states the core action and resources, and the second adds the critical behavioral note. There is no unnecessary fluff or repetition; every word contributes to understanding the tool's purpose and effect.

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 simple schema (one string parameter, no output schema) and clear annotations (destructiveHint), the description is largely complete. It explains the action, resources, and a key side effect. However, it does not specify the expected format of the state file (e.g., .json, Playwright storage state format), which could cause issues if the agent needs to create such a file. This minor gap prevents a perfect score.

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 schema already provides 100% coverage for the only parameter 'filename', describing its purpose and type. The description adds no new details about the parameter (e.g., expected file format, path conventions, or supported storage states). According to the rubric, with high schema coverage, baseline 3 is appropriate; the description does not improve nor detract from parameter understanding.

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 'restore storage state' and includes the concrete resources 'cookies, local storage' and the source 'from a file'. This clearly distinguishes it from siblings like browser_cookie_set or browser_localstorage_set, which operate on individual items rather than restoring a full state snapshot.

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 briefly mentions that it clears existing cookies/local storage before restoring, which implies a destructive action. However, it does not explicitly state when to use this over alternatives like browser_cookie_set or browser_localstorage_set for individual items, nor does it mention context like preparation of storage state files or typical use cases (e.g., restoring a session).

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