bilibili_favorite_folders

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

Annotations already declare readOnly, idempotent, non-destructive, open-world. The description contributes the non-obvious default-account fallback, which is genuine added context, but says nothing about auth requirements, pagination, or what a folder entry contains.

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?

One compact sentence with the list action first and the important default condition attached. Nothing wasted, though the parenthetical default is slightly buried after the semicolon.

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?

No output schema exists, so the description should hint at the return shape (folder IDs and names, needed to feed bilibili_favorite_items) and the auth precondition; neither is present. Adequate to call, insufficient to chain.

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% for the single parameter, so the description does the useful work of explaining the meaning of omitting up_mid. It still never defines what up_mid designates (a user mid) or whether passing another user's mid is permitted or private.

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 — listing favorite folders (收藏夹) — which is clear enough to distinguish it from siblings like bilibili_favorite_items (folder contents, not folders). The tag '[收藏]' adds a category hint but the description does not explicitly contrast with the nearest sibling.

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?

It gives a conditional default (omit up_mid to target the currently bound account), which is real usage guidance, but it never says when to use this versus bilibili_favorite_items or whether authentication is required for the default path.

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