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

Annotations declare a non-idempotent, non-destructive, open-world write; the description adds substantial context beyond them — the return shape {id, status:"importing"}, that processing is async, the exact polling/webhook completion path, and the webhook payload semantics (status: complete|failed). This is exactly the behavioral detail a mutating async tool needs.

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 purpose, then parameters, then return/async follow-ups; every clause carries signal (return shape, async path, webhook). Slightly dense with parenthetical em-dashes, but no filler sentences.

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 an output schema exists, return values need not be explained, yet the description still helpfully states {id, status:"importing"}. With async behavior, follow-up calls, and webhook semantics all covered, an agent has everything needed to invoke and chain this 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 100%, so the baseline is 3. The description correctly notes url must be https and identifies the key fields, but it labels contentType as 'optional' while the schema marks it required (required: ["url","filename","contentType"]) — a material inconsistency that could lead an agent to omit a required field. It also omits the size/audioRole fields, which the schema itself documents.

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 ('Import a media item into your library') and immediately scopes it against the sibling upload path ('single call, no upload protocol'), distinguishing it from create_upload/finalize_upload/prepare_media. An agent can select it without opening the schema.

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 frames itself as the 'agent-friendly ingest path' vs. the upload protocol alternative, and names concrete follow-ups: wait_job(kind="media", id=...), create_webhook on media.completed, and downstream consumers (get_media_context, suggest_briefs, composition source). When-to-use and next-step routing are both covered.

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