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

No annotations exist, so the description carries the full burden. It discloses a genuine behavioral trait not in schema fields — the 0.002 USDC cost and x402 payment model — which is valuable. However it doesn't describe what happens when there's no edge (zero/negative size?), the assumptions of the formula, or any limits, leaving the behavioral picture incomplete for a no-annotation mutation-like paid tool.

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 tight sentences, outputs front-loaded, pricing last. No filler. Minor deduction for the vague 'Formula agent:' label taking the lead position instead of a concrete verb.

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?

With no output schema and no annotations across 7 params, the description should convey the return shape and edge-case behavior. It names the four computed values (useful) but does not explain their format or the no-edge response, so an agent still lacks a complete picture.

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 only 29%, so the description must compensate. It does partially: 'capped at a maximum risk per trade' maps to maxRiskPct and 'position size for a stop-loss' maps to stopLossPct. But avgWin/avgLoss units, bankroll semantics, and the meaning of winRate scaling beyond the schema's '0-1' note are undefined.

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 computational verb+resource set: computes Kelly fraction, half Kelly, expectancy, and stop-lossed position size, capped by max risk per trade. No sibling tool competes for this function, so the resource is unambiguous. Slight deduction because 'Formula agent' is odd framing and it doesn't specify the shape of the answer, only the concepts.

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?

Usage is implied (position sizing / edge detection) but never stated as when-to-use. 'Tells you when there is no edge' hints at a precondition, yet there is no explicit when/when-not guidance or mention of the required win/loss statistics as a prerequisite.

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