Edit existing video

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

The description discloses that the tool blocks until rendered and returns the new video URL, adding value beyond annotations. It also mentions credit costs for new/changed photos. While annotations already indicate mutation (readOnlyHint=false) and no destruction (destructiveHint=false), the description enriches with synchronous behavior and cost implications.

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?

The description is concise with no redundant sentences. It front-loads the primary purpose ('Edit an existing video by videoId without re-rendering unchanged clips'), then efficiently covers cost, optional omissions, and behavior. Every sentence adds value.

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 no output schema, the description states it returns a URL. It covers core usage patterns but lacks details on some parameters (e.g., propertyCharacteristics, isVertical) and does not explain error cases or pagination. For a tool with 9 parameters and nested objects, it provides a good overview but is not exhaustive.

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 low (33%), so the description compensates by explaining high-level semantics: omitting images leaves timeline unchanged, omitting music/voice/branding/ending text leaves them unchanged, and images parameter is the full ordered list. This contextualizes parameters effectively, though some parameters like 'isVertical' and 'propertyCharacteristics' are not addressed.

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 clearly states the tool edits an existing video by videoId, emphasizing it avoids re-rendering unchanged clips. It distinguishes from create_video by specifying that only new/changed photos cost credits, while reordering, music, voice, branding, and text re-stitch for free. This gives a precise verb-resource-scope and differentiates from siblings.

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?

The description provides explicit guidance on when to omit fields (e.g., 'omit images to change only audio/text/branding while keeping the current timeline'), which is helpful. However, it does not contrast directly with the sibling 'pedra_edit_via_prompt' or explicitly state prerequisites (e.g., video must exist from pedra_create_video). The context is clear but lacks alternative choices.

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