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

Annotations only declare the generic safety flags (destructiveHint=false, idempotentHint=false). The description adds high-value behavior beyond them: this is the biggest credit spend, dry_run quotes the estimate, animate defaults to a clip or talking-head model, a refused render leaves the segment unchanged, and there is a documented recovery path (segment_restructure change_type=to image keep_image=true).

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 the critical instruction to run dry_run first, and each subsequent sentence carries distinct operational content. It is dense, multi-clause prose, but almost no sentence is filler.

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 10-parameter mutation tool with no output schema, the description covers cost/estimation behavior, refusal handling, defaults, and post-run verification paths, which is what an agent needs. Nothing essential for correct invocation appears missing.

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 baseline is 3, but the description adds cross-parameter semantics the schema does not: overrides need segment_numbers plus what=images/clips, and animate uses segment_number with optional talking_head. It leaves a few params (model, settings, editable_sections) to the schema alone.

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 (render) and resource (segment images and clips) and immediately distinguishes its two sub-actions, generate and animate, with the scope of each. It also flags the differentiating stakes ('the biggest spend in the video'), which no sibling touches.

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?

Explicit when-to-use and when-not: dry_run=true first and get user confirmation; generate without segment_numbers = everything not yet rendered, with them = those segments including finished ones; overrides require segment_numbers and what=images/clips. It also routes to verification via storyboard_read action=segment_assets and view_image.

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