Make a local video from images

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

Annotations already establish that this is a non-read-only, non-destructive, non-idempotent closed-world operation. The description adds useful behavior beyond that: silent H.264 output, output verification, frame/dimension/timing limits, and no external encoder download. It stops short of stating overwrite behavior for output_path or error recovery details.

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-loads the core operation, then adds constraints and environment requirements in compact sentences. Every sentence contributes useful selection or invocation context with no 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?

Given 10 parameters, low schema coverage, and no output schema, the description covers the high-level capability, environment, and hard limits well. However, it leaves significant invocation details undocumented, especially individual parameter meanings and output overwrite behavior.

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 only 10%, so the description must compensate, but it only broadly mentions size, timing, fit, and quality controls. It does not explain key parameters such as input_paths limits, durations_ms versus duration_ms precedence, background, fit enum semantics, or quality levels.

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 and resource: encode ordered still JPEG/PNG/WebP images into a silent H.264 MP4. This is precise enough to distinguish it from sibling media tools such as gif_create, gif_to_mp4, video_join, and image_layout.

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?

Provides clear usage context through hard limits (60 seconds, 1800 frames, 1080p) and an environment requirement (local browser with native H.264 encoder). It does not explicitly compare with alternatives, but the use case is strongly implied.

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