Update storage settings

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

Annotations already declare destructive and non-idempotent, and the description adds real depth on top: replace-not-merge semantics, null-clears-fields behavior, silent dropping of ACL rules for nonexistent users, and the fact the response reflects what was actually saved. It also states the required permission (account:settings:write), which annotations cannot express.

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?

Front-loads the core action, then layers replace semantics, ACL caveats, header relationship, and authentication – each sentence earning its place. No filler or restatement of the title.

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 mutation tool with a complex nested union body and no output schema, the description supplies the missing pieces: destructive replace behavior, auth/permission requirement, override relationship to the request header, and a hint about verifying the returned settings. Nothing an agent needs to call it correctly is 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 coverage is 100%, so the schema already documents each field including null semantics, giving a baseline of 3. The description adds value beyond that by explaining the union-body replace contract ('always send the full desired configuration') and warning that saved rules may differ from those sent – semantics the per-property schema does not convey.

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 precise verb (replaces) and resource (account-level storage lifecycle settings) with scope narrowed to newly uploaded fal CDN files. This cleanly distinguishes it from the sibling get_storage_settings (read) and set_storage_file_acl (per-file, not account-level) without opening either schema.

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?

Gives clear operational guidance – 'always send the full desired configuration' because omitted/null fields reset to defaults – and notes the per-request header that overrides these same settings. It stops short of naming a sibling tool or an explicit when-not condition, so it is strong context rather than full alternate-tool routing.

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