视频理解

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

With no annotations, the description carries full burden. It discloses the critical behavior that backends without native video capability will automatically use frame sampling. This transparency helps the agent understand a potential fallback. No mention of destructive effects or auth needs, but the tool is essentially read-only.

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 exceptionally concise with two sentences. The first sentence states the core purpose, and the second adds important behavioral and usage context. Every word is meaningful with no redundancy.

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 that an output schema exists (not shown but referenced), the description need not cover return values. It covers main functionality, fallback behavior, and usage context. It could mention question scope or limitations, but for a video tool with sibling tools that are image-focused, it is sufficiently 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 coverage is 100%, so baseline is 3. The description does not add meaning beyond the schema; it only provides general usage context without elaborating on parameters like question formatting or detail_level behavior. Baseline score 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?

The description clearly states the tool understands video (timeline + frames) and answers questions, with a specific use case of screen recordings or short videos. It distinguishes from sibling image tools by focusing on video and mentioning automatic frame sampling for backends without native video capability.

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 gives clear context by specifying when to use the tool ('analyze screen recordings or short videos'), which implies alternatives for static images. However, it does not explicitly state when not to use it or name alternative tools.

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