session_save

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

With no annotations, the description carries the full burden and does disclose what is saved (cookies, localStorage/sessionStorage), the target session, and the output location. However, it does not state whether an existing file is overwritten, what happens on failure, or whether saving has any side effects on the live session.

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?

A single, well-structured sentence packs in the action, the scope, the data captured, the destination, and the companion restore tool. There is no filler or redundant restating of the tool name.

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 two-parameter tool with no output schema and no annotations, the description is largely sufficient: it explains both parameters and the intended usage. The only meaningful gap is the omitted overwrite/failure behavior, which an agent might need for safe invocation, but it is not critical for a typical save operation.

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 provides no descriptions for 'name' or 'sessionId' (0% coverage), but the description compensates: 'name' is clearly used in the file path, and 'active (or given) session' explains the optional sessionId semantics. This gives an agent the meaning it needs beyond bare parameter names.

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?

States a specific verb ('Save'), a precise resource ('session's cookies + localStorage/sessionStorage'), and an exact destination ('~/.bfa/state/<name>.json'). It also clearly pairs with session_restore, which distinguishes it from the related sibling and from other browser/session tools.

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 signals the intended workflow ('for later restore with session_restore') and clarifies the active-or-given session choice. It does not explicitly list exclusions or alternatives, but the pairing with session_restore gives an agent enough context to decide when this tool is relevant.

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