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

Annotations only declare idempotent/destructive/readOnly hints; the description concretizes them — an already-present file returns its existing Asset ID (idempotency), Trash or still-uploading files are returned with a reason instead of failing opaquely, and 'Nothing is copied or charged' rules out billing and duplication side effects.

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?

Purpose is front-loaded in sentence one, followed by input provenance, return semantics, edge cases, cost, and the required follow-up. Five short sentences, each carrying distinct operational information with no filler.

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?

There is no output schema, so the description must carry return semantics — and it does: Asset IDs returned per file, re-returned for duplicates, and per-file failure reasons. Combined with the follow-up instruction for processing videos, nothing an agent needs to call this correctly 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% and both parameters are documented in the schema, including id provenance and the projectId override semantics. The description reinforces that ids come from search_library but adds no syntax or format detail beyond what the schema already provides, so the baseline 3 applies.

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+destination: add files from the user's Library into the open project. It also implicitly distinguishes itself from search_library (source of ids) and patch_film (placement), so an agent can route without opening sibling 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?

Explicitly routes: ids come from search_library, results are placed with patch_film, and if a video is still processing call wait_for_asset before placing. This covers the full before/after workflow rather than just the call itself.

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