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

With no annotations, the description carries the burden and does meaningful work: it discloses the return shape (compact cards enumerating REF id, link, thumb, length, aspect, views, measured metrics, and rationale) and notes the library is pre-dissected. It omits auth/rate-limit behavior and the partial-match fallback detail (which lives in the schema), so not fully complete.

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?

A single dense paragraph that front-loads what the library is and what results contain before the call-to-action routing. Every clause carries information; it is slightly long but nothing is redundant boilerplate.

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 13-param tool with no output schema, the description compensates well by enumerating the returned card fields and the metrics available. It does not explain the ordering/pagination mechanics, but those are covered by schema descriptions, so an agent has enough to call it 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?

Schema coverage is 77% with 13 params, so the schema already documents most fields including enums and defaults. The description adds only that a REF id or link can be passed via a ref, and does not enrich the meaning of brand, category, made_with, or the seconds filters beyond the schema. 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?

States a specific verb+resource (search a curated video library) and pins the scope with concrete content types and counts (4,000+ dissected top-performing videos). It also names the downstream siblings (get_blueprint, plan_video), so an agent can distinguish this discovery tool from the retrieval/planning tools without opening their schemas.

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?

Gives explicit when-to-use context ('find references before making a video') and names the follow-on alternatives to pass a ref into. It stops short of stating when NOT to use it (e.g. use get_collection for curated sets), so it is clear context rather than full when/when-not routing.

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