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

Annotations declare the mutation profile (readOnlyHint=false, destructiveHint=false, idempotentHint=false), and the description adds genuinely new behavior: the call is free, edits are gated on base_spec_version (optimistic concurrency), length growth raises the pending-approval price, and the response carries the new version plus undo_ops. It doesn't spell out what happens on a version mismatch, which keeps it below 5.

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 lead ('Free.' + purpose + version source) is well front-loaded, but the op catalogue is one semicolon-chained run-on with no line breaks or grouping, which makes it slow to scan for a single op. Every clause carries information, so it is dense rather than padded, but the structure costs it.

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?

With no output schema, the description correctly closes the loop by naming the return values (new version, undo_ops). Constraints on voices, media, and length/pricing are all present; only failure-mode behavior for a stale base_spec_version is 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 0% and the ops item schema is only {op: string} with additionalProperties, so the description is the sole source of op semantics — and it delivers, mapping payload keys for vo.set, text.set, scene.insert, scene.timing, cta.set, music.set and pace.set. base_spec_version's provenance is also explained; only video_id is left implicit.

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 ('Applies edit ops to a storyboard') plus a crucial state qualifier ('that waits for approval'), which separates it from approve_storyboard and get_storyboard without opening a schema. The enumerated op vocabulary makes the scope concrete.

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?

Explicitly tells the agent to source base_spec_version from get_storyboard and voices from get_options, and restricts media to the project — real usage prerequisites. It stops short of naming when to prefer edit_video or approve_storyboard instead, so no exclusions are stated.

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