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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered. The description goes further by disclosing the payment model ($0.10 per call via x402 on Base, or 20 for $1.00 with atlas_buy_pack), which is significant operational context an agent would not otherwise know. It stops short of describing the return shape or latency.

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?

Three sentences: what the kit is, how to use it, and cost. The deliverable is front-loaded and the pricing trailer is separated cleanly. The first sentence is dense with parenthetical asides, but nothing is redundant.

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 nine-parameter, nested-object generation tool with no output schema, the description usefully sketches what the kit contains and points to the next step (atlas_lint). Pricing is covered. Only the actual return format is left implicit, which is acceptable given the content overview.

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 all nine parameters are already documented in the schema. The description lightly reinforces meaning ('shot size — where the tell can be seen', the target model's rules) but adds no syntax or format detail beyond what the schema provides. Baseline 3 is appropriate.

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 description names a concrete deliverable (a direction kit for a character state) and enumerates its contents — beat-by-beat behaviour fitted to shot size, eye life, breath, target-model rules, a voice delivery line — which is specific enough to distinguish it from generic drafters. It also names atlas_lint as the follow-up. It does not, however, differentiate itself from close siblings like atlas_draft or atlas_show.

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 gives a workflow chain ('Write the acting prose from it, then atlas_lint the prose'), which implies when to reach for this tool, but offers no explicit when-to-use-vs-alternatives guidance against atlas_draft, atlas_show, or atlas_journey. Usage is inferable but not spelled out.

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