meta get video sources

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

The description adds meaningful behavioral context beyond the readOnlyHint/idempotentHint annotations: URLs are freshly minted, signed URLs expire quickly. This is exactly the kind of behavioral nuance annotations alone do not provide, and it matters for agent behavior at download time.

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?

Two concise sentences with no wasted words. The core behavior is front-loaded — 'Resolve fresh download URLs and thumbnails' — and the temporal constraint follows immediately after the colon, making the key call-time behavior prominent.

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 read-only resolver with full schema coverage, an output schema present, and safety annotations provided, the description covers the purpose, the trigger condition, and the key behavioral caveat. Nothing essential for a correct invocation is missing.

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 100%, so the schema already documents adAccountId, videoIds, and pageId thoroughly. The description reinforces that videoIds are ad-video IDs to resolve and that URLs are fresh/short-lived, but it does not need to add much beyond the schema.

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 is specific and action-oriented: 'Resolve fresh download URLs (source) and thumbnails for specific ad videos.' It clearly identifies the resource, the verb, and the distinguishing trait — freshness/signed URLs — which separates it from nearby siblings like meta_get_uploaded_video and meta_list_ad_videos.

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 explicitly says 'Call this at download time: the returned URLs are signed and expire quickly,' giving the agent a clear temporal condition for when to use this tool. It does not explicitly name alternative tools or exclusions, but the download-time framing is clear enough for routing.

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