get_video_info

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

With no annotations, the description carries the full burden and handles it well: it discloses the fallback semantics, subtitle-language behavior, and — critically — includes a security warning that returned Bilibili text is untrusted and must not be executed as instructions. It doesn't mention rate limits or error semantics, but the core behavioral and safety traits are well covered.

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?

Four concise sentences efficiently cover purpose, fallback, features, credentials, and security. The warning is duplicated in Chinese and English, which is slightly redundant but justifiable given its safety-critical nature and the mixed-language audience.

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 4-parameter tool with no output schema and no annotations, the description covers the essentials: what it does, how subtitle selection works, fallback behavior, and a security caveat. Minor missing pieces are output format details and error behavior, but it's adequate for agents to invoke properly.

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% with detailed per-parameter descriptions (enum values, min value, defaults, behavior of exclude_ai_subtitles). The description adds tool-level context (e.g., preference language support) but doesn't significantly go beyond the schema's parameter documentation; baseline 3 is appropriate.

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?

"获取 Bilibili 视频信息" is a clear verb+resource with specific behavioral framing: it prioritizes subtitles, falls back to introduction/tags, and supports language/multi-P selection. This differentiates it from siblings like get_video_metadata and get_video_transcript by disclosing the subtitle-vs-fallback priority logic, which is unique to this tool.

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 provides an explicit sibling alternative reference ('For credential help, call get_credential_setup_instructions') and explains the tool's contextual behavior (preferred language selection, multi-P support, AI-subtitle filtering). However, it doesn't explicitly clarify when to choose this over the closely related get_video_metadata or get_video_transcript, leaving some ambiguity in tool selection.

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