save_session

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

Annotations declare readOnlyHint=false, destructiveHint=false, openWorldHint=true; the description adds context beyond that by warning that the resulting file contains credentials equivalent to being logged in and must be kept private, plus the non-profile browser behavior. It doesn't say where the file lands or how it is named/overwritten, but the security disclosure is the high-value part.

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?

Two sentences, zero waste; the primary action comes first and the security caveat and sibling reference follow immediately. Nothing repeats the name or annotations.

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?

An output schema exists, so return values need not be described. The description covers purpose, the recovery path (load_session), the security implication, and the non-profile browser nuance — enough to call it correctly; only file location/naming specifics are absent.

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% for the single 'name' parameter. The phrase 'to a named file' hints that the parameter names the file, but it does not explain the default ('default'), file naming conventions, or overwrite behavior, so compensation for the coverage gap is only partial.

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?

Specific verb+resource: 'Save cookies and localStorage of the current browser to a named file'. It explicitly separates itself from sibling cookie tools (get_cookies/set_cookies) by describing a persisted session file, and even names the consuming tool, load_session.

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 gives a clear use case — reuse a login later via load_session — and notes it works on a throwaway non-profile browser, which is exactly the situation where its sibling alternatives would not suffice. It stops short of stating exclusions or prerequisites (e.g., whether a page must be loaded first).

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