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

Far beyond what the annotations declare: credits are spent at prismposter.com parity rates, the original clip is preserved, output lands in the PrismPoster library, and any request needing human consent returns approval_required with nothing running. It also discloses a pre-charge refusal policy, which is exactly the kind of gating behavior an agent must anticipate. Fully consistent with destructiveHint=false and readOnlyHint=false.

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 action and its invariant, then cost and approval semantics. Dense but every sentence carries decision-relevant information; the long parenthetical listing consent cases is the one spot that could be tightened.

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 an 8-parameter, no-required-field mutation tool with no output schema, the description still covers what is returned (a new clip, original kept), where it is stored, what it costs, how failures/approvals surface, and policy refusals. An agent has everything needed to call it correctly and interpret the result.

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 would be 3, but the description adds workflow-level meaning the schema lacks: the quote_job pre-pricing step, the resolve-then-rerun approval loop keyed on approval_id, and the cost implication behind choosing a resolution. It does not separately explain engine, aspect_ratio, or idempotency_key beyond what the schema already says.

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 ('Change a clip the account made') plus an enumerated scope of edit types and the invariant ('keeping everything else'), with a clear constraint on clip length. An agent can distinguish it from create_video, extend_video and remake_* without opening any schema.

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?

It clearly establishes the operating context: quote_job prices first for free, the approval_required path halts execution, and content involving minors or public figures is refused before charging. It also constrains length ('up to one take long; for longer clips change only the last stretch'). It does not explicitly name sibling alternatives such as extend_video for longer material, so it stops one step short of a 5.

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