describe_video_url

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

With no annotations, the description fully discloses behaviors: temporary download to temp_media/ with deletion, YouTube cloud-read without download, public-only restriction, daily quota limits, per-second billing, unsupported platform errors, parameter precedence (prompt overrides persona/hint), and output characteristics. This is comprehensive beyond minimal expectations.

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 well-structured with an overview, bullet points, warning, parameter references, and returns. It is somewhat lengthy but every part adds necessary detail for a complex tool. The redundancy of listing parameters after saying they match describe_video is minor and acceptable for self-containment.

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?

Given no output schema and 6 parameters, the description is highly complete: it covers input formats, limitations, side effects, error cases, parameter dependencies, and return value format (with usage stats/truncation hints). No critical context is missing for an agent to invoke the tool correctly.

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?

Despite 0% schema_description_coverage, the description thoroughly explains every parameter: url supplies type specifications, prompt/persona/hint precedence, low_resolution purpose, and max_output_tokens default with 2048 lower-limit protection. This fully compensates for the schema's lack of descriptions.

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 clearly states it downloads from a direct link or cloud-reads from a YouTube page, then sends to Gemini for Chinese timeline-segmented description. This distinguishes it from sibling describe_video by focusing on URL inputs, with explicit mention of supported URL types.

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 provides clear context on when to use: direct video file links or YouTube page links. It also lists exclusions (Bilibili/Douyin/TikTok unsupported) and error behavior. However, it does not explicitly contrast with sibling describe_video beyond referencing it for parameter semantics, so a slight gap in direct alternative guidance exists.

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