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

Annotations already cover the safety profile (non-destructive, idempotent, closed-world), and the description adds genuinely new behavior: it consumes AI credits and returns a new pending media asset requiring polling. Those are the two things an agent most needs to know before invoking an async, credit-spending job.

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?

Three short sentences, front-loaded with the action, then prerequisite, then side effects and next step. No filler or repetition.

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?

Despite an existing output schema, the description still conveys the async contract (pending asset + polling), the credit cost, and the required prerequisite call. An agent has everything needed 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 coverage is 100%, so every parameter including assetId, targetResolution, projectId, workspaceId, and idempotencyKey is already documented with format and defaults. The description only restates the resolution options, adding no meaning beyond the schema. 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 (upscale), the single resource affected (one stored video asset), the provider, and the two valid outputs (1080p/4k). It is clearly distinguishable from media_upscale_estimate, which it explicitly defers to.

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 an explicit prerequisite ('Call media_upscale_estimate first') and a follow-up path (poll with media_assets_get). It doesn't spell out when NOT to use it, but the sequencing guidance is strong and actionable.

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