get_favorite_folders

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

With no annotations, the description carries the full burden, and it does disclose the important behavioral trait: the tool always operates on the currently logged-in account, username matters only for Cookie-only HTML clients, and API clients have the parameter ignored. That is exactly the auth-context disclosure an agent needs. It stops short of describing pagination, ordering, or size limits of the folder list.

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 clearly sectioned into purpose, parameters, and return, and front-loads the one-line purpose. Every sentence is informative, though the return block partially restates what the existing output schema already defines.

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 single-optional-parameter read tool with an output schema, the definition is nearly complete: purpose, auth semantics, and the folder_id="0" edge case are all covered. The minor gap is that the return-value description duplicates the output schema instead of focusing on folder ordering, stability, or how the ids should be reused.

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% and the parameter is just an untyped-in-practice optional string with an empty default, so the description must supply all meaning — and it does: it explains precisely when username is required (Cookie-only HTML clients without auth.username), when it can be omitted, and that API clients ignore it entirely. This is meaning fully beyond the schema.

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 verb and resource — retrieve the favorite folders (收藏夹目录) of the logged-in account — which is concrete enough to distinguish it from album-oriented siblings like browse_favorite_albums. However, it never explicitly says 'this returns folders, not albums' or names a sibling, so the differentiation is left to inference.

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?

There is no explicit when-to-use / when-not-to-use guidance versus browse_favorite_albums or search_album. The only guidance is indirect but useful: the note that folder_id="0" queries all favorites hints that the returned ids feed another call, which implies why an agent would call this first.

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