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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered; the description then adds genuinely non-obvious behavior: status stays COMPLETED while regenerate_scene runs and video_url is stale, plus that failures return a reason and a credits entry with charged/refunded amounts. These are exactly the behavioral gotchas an agent could not infer from structure.

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 return contents before the pipeline, the next_action warning, and the failure case, in descending order of importance. Dense but every clause carries information; the parenthetical example embedding a sample stage string is slightly heavy but illustrative rather than 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?

No output schema exists, so the description must carry the return contract — and it does, describing the key fields, the stage sequence, the next_action priority, and the failure payload. Nothing an agent needs to poll and interpret this tool correctly 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?

Only one parameter and schema description coverage is 100% — the schema already explains job_id and where to obtain it (create_video, create_from_template, list_videos). The description adds nothing about the parameter, which is appropriate here, 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?

States a specific verb+resource ('check a job's progress') and immediately enumerates what comes back (stage, progress_percent, per-stage statuses, next_action). The pipeline enumeration (SCRIPT -> AUDIO -> KEY_FRAMES -> CLIP_GENERATION -> VIDEO_STITCH) makes the scope unmistakable and clearly separates it from sibling actions like regenerate_video or retry_step.

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?

Gives clear operational guidance: 'share it with the user while they wait' establishes the polling context, and 'Follow next_action rather than status alone' is an explicit usage rule with a stated failure mode. It stops short of naming sibling alternatives (e.g. get_video vs. this tool, or when to use retry_step after a failure), so it is not a full when/when-not/alternatives treatment.

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