Overlay video

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

Annotations already declare destructive=true, idempotent=false, openWorld=true, so the safety profile is covered. The description adds genuinely new operational context: provider scopes, locks, credits apply, plus the mandatory confirmation gate and one-submission-only constraint. These are real behavioral facts not present in the annotations.

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, front-loaded sentences with no filler; the endpoint and V5 context lead, followed by the confirmation constraint. It is efficient, though it spends its limited budget on procedural metadata rather than describing the operation.

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 complex, destructive, non-idempotent video operation with a deeply nested payload and no output schema, the description covers the confirmation/credit mechanics but omits what the tool actually renders and any output or job-polling expectations. It is minimally adequate given the rich schema but leaves real gaps.

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%, so both the top-level params (account, confirm, payload, payload_file) and nested payload fields are documented in the schema itself. The description adds no parameter-level meaning (e.g., no explanation of the x/y/position interplay or audio mixing modes), 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?

The description only restates the endpoint path ("POST /v5/tools/overlay_video") and labels it a "Current Bannerbear V5 operation". It never explains what overlaying a video onto another video actually does, and it draws no distinction from siblings like overlay_image, add_cover_art, or concat_videos. Purpose is inferable only from the name/title, not the description text.

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?

It states a procedural precondition ("Mandatory confirmation before provider execution; one submission only") but gives no guidance on when to choose this tool over the many other video tools in the sibling list. There are no when-to-use or when-not-to-use conditions relative to alternatives.

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