ASO Unit Economics

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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint=false and destructiveHint=false, so safety is covered; the description reinforces this with 'pure calculation, no network'. It also surfaces the domain rule that apple_cut is 0.15 for Small Business else 0.30, which is genuine behavioral context beyond the annotations.

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 core purpose, then compact 'Use when / Not for / Returns' segments; every sentence carries information and there is no filler despite covering purpose, routing and output shape.

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 no-required-param, pure-calculation tool with full schema coverage and an output schema, the description supplies the missing routing context and the domain-specific apple_cut rule. An agent has everything needed to select and invoke it correctly.

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 every parameter (including defaults and the Small Business cut) is already documented in the schema. The description only summarizes the input domain as 'prices, credits and AI cost' and largely repeats the apple_cut rule, adding little beyond the structured field text.

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 (Compute) plus the exact outputs (margin, break-even, warnings) and inputs (prices, credits, AI cost), and adds a scoping qualifier ('pure calculation, no network'). It explicitly names the sibling it is not (pricing_unit_economics), so an agent can discriminate it from the large tool list.

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?

Contains explicit 'Use when: idea/scaffold stage pricing decisions' and 'Not for: measured-cost economics for a built app (use pricing_unit_economics)', giving both the trigger condition and the named alternative. Nothing is left to inference.

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