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

With no annotations, the description carries the full burden and does well: it discloses the output shape (image + image + image + text), that media is saved to disk with file paths in the result, the pricing model ($0.19 deposit in Nano/XNO, settled at cost + 20% with change returned), that no account is needed, and measured latency/cost (~2m 4s, last run $0.0652). It omits the payment/watch lifecycle, but that gap is covered by the _payment_id schema description.

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 purpose and the closing cost/latency sentences are front-loaded and earn their place, but the middle pipeline chain is a long, dense arrow/semicolon run that is hard to parse, and the prose summary of it trails off with an ellipsis ('Muse Edit uses the draft…'). It is information-rich but structurally uneven.

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 high-complexity 6-parameter, multi-model, pay-per-call tool with no output schema and no annotations, the description covers output composition, storage, cost, latency, and the internal pipeline. The remaining gaps are selection guidance relative to siblings and the asynchronous payment/watch flow, the latter partially covered by the schema.

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 100%, so the baseline would be 3, but the description's pipeline notation maps each parameter name to its position and role in the chain (First scene → Muse opens the story, Next beat → stages the next beat, Continuity rules → join, Continuity notes and Draft continuity check → llm checks), adding ordering and dependency semantics the schema doesn't convey.

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?

The opening sentence gives a specific verb+resource ('Make a two-frame story through a handoff between models') and names every participating model and its role, so the agent understands this is a multi-model two-frame pipeline rather than a single-image generator. It does not, however, explicitly contrast itself with siblings like tiny-world-film or photo-to-video, which would be needed for a 5.

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?

There is no when-to-use or when-not-to-use guidance and no mention of the sibling tools that also produce narrative imagery (tiny-world-film, character-sprites). The description explains how the pipeline works internally but never tells the agent which situation should select this tool over its alternatives.

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