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

Beyond the annotations (which already declare non-readOnly, idempotent, openWorld, non-destructive), it discloses asynchronous return semantics, the credit/quotas model (no credits for import, storage quota consumed, 5 credits for analyze_after_import), and unsupported input classes. This is exactly the value-add behavioral context annotations cannot carry.

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?

Front-loaded with the core action and constraints, then each following sentence adds a distinct non-redundant fact (async flow, cost model, analysis option, exclusions). No filler or repetition of the title/name.

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?

An output schema exists, so return values needn't be described, and the description still supplies the async polling flow an agent needs to actually complete the task. For a 3-parameter import tool this covers everything required to invoke and follow up 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 description coverage is 0%, so the description must compensate and only partly does: it fully explains analyze_after_import (runs the analyst for 5 credits; false to use your own model). url is self-evident from the name, but product (single-value enum 'kuro') is never mentioned, leaving one parameter undocumented in both places.

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 (import) and resource (one public YouTube/Facebook/TikTok video) plus its destination (into the Library), with concrete scope limits (10 minutes, 250 MB). This cleanly separates it from generic siblings like import_media and from upload flows like create_upload/complete_upload.

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?

Explicitly routes the agent: call this, then poll get_video_import until ready and reuse its upload_id. It also names alternatives for the analysis path (get_video_analysis_bundle and save_video_analysis) and states exclusions (private videos, playlists, live streams).

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