save_state

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

With no annotations, the description carries the full behavioral burden. It discloses the main side effect (writing cookies + localStorage to a storageState JSON at path), but it does not mention whether the file is overwritten, whether an active authenticated session is required, or what happens if the session has no cookies/localStorage.

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, well-paced sentence with no filler. The core action and destination are front-loaded, and the 'portable, reusable authenticated session' addition earns its place by explaining why this export is valuable.

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 one-parameter tool with an output schema present, the description covers the essential what and where. However, it is incomplete on edge-case behavior such as overwrites, failure modes, and prerequisites, which an agent might need to invoke it confidently without annotations.

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 coverage is 0%, so the description must compensate. It clarifies that 'path' is the destination for the exported JSON, which is useful, but it does not provide details like file naming conventions, relative vs. absolute paths, or extension expectations beyond the implied JSON.

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 a specific action (export), a specific resource (current session cookies + localStorage), a concrete output format (Playwright storageState JSON), and a destination (path). It is clearly distinguishable from sibling tools like navigate, click, or read.

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 phrase 'a portable, reusable authenticated session' gives clear context for when to use this tool: persist auth state for later reuse. It does not explicitly name alternatives or state when not to use it, so it falls just 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.