Get Video Evidence

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

The description adds value beyond annotations by stating that the tool 'never invents detail beyond what was actually recorded', which is a behavioral guarantee. Annotations already provide readOnlyHint=trueتریidempotentHint=true and destructiveHint=false, but the description adds specific context about data fidelityesternity. It does not contradict annotations and accurately reflects a read-only lookup operation.

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 concise, with two sentences. The first sentence clearly states the purpose and constraint, and the second provides a concrete use case. It is front-loaded with the core function and behavioral guarantee. It could be slightly more structured, but it is effective and does not waste words.

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 the tool's moderate complexity, with 2 required parameters and an output schema, the description covers the essential aspects: what it does, when to use it, and behavioral guarantees. It mentions the ids needed and where they come from in the schema. The description is sufficient for an agent to understand when and how to use this tool correctly, especially with the output schema and annotations providing additional context.

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?

The input schema fully describes both parameters (video_id and evidence_id) with explanations of where they come from. The description does not add additional parameter semantics beyond what the schema provides. Since schema description coverage is 100%, the baseline score of 3 is appropriate; the description does not need to repeat the parameter details.

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's function: to look up evidence for a single Video Map fact by id. It uses a specific verb ('looks up') and the resource ('full evidence behind a single Video Map fact'). It differentiates itself from siblings by explicitly referencing get_video_map and get_video_entity, making it clear that this tool retrieves evidence details rather than the map or entity data itself.

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 explicit guidance on when to use this tool: to double-check a specific claim before treating it as authoritative, such as confirming a reference's evidence_level. It also implies when not to use it (e.g., when you need the full map or entity, use the mentioned siblings). The mention of alternative tools (get_video_map, get_video_entity) provides clear routing, and the use case ('double-check a specific claim') is well-defined.

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