bili_discover

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

With no annotations, the description carries the full burden and does well: it discloses that refresh builds a new source snapshot rather than paginating the old one, warns that the platform may return duplicate videos, and notes the mutual exclusion of refresh and cursor. Gaps remain on auth requirements (e.g., whether 'following' needs login) and on read-only safety, which no annotation confirms.

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-loaded with the purpose, then dense semicolon-delimited clauses that each carry distinct information about refresh, cursor, and sources. Slightly telegraphic phrasing ('actual source and personalization limits returned') costs a little readability.

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 needn't be described, and the description covers the interaction between the two non-obvious parameters well. Missing detail on limit behavior, category semantics, and authentication for the 'following' source keeps it short of complete.

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% with 5 params, so the description must supply all meaning. It explains cursor, refresh, and enumerates the source values, but says nothing about limit (default 10) or category ('All'), leaving two of five parameters completely undefined.

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 and resource ('Discover video candidates') and adds a defining scope constraint ('without a BV'), which separates it from BV-based tools like bili_video_info and from bili_search. An agent can identify the tool's role without opening the 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?

Explicitly states the default mode (homepage), the two continuation modes (refresh=true for a new fetch, cursor for the saved snapshot), and that they cannot be combined. It never routes to siblings like bili_search, bili_related, or bili_browse_advance, so the alternative-selection guidance is incomplete.

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