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

Annotations already cover the safety profile (readOnlyHint=true, destructiveHint=false, openWorldHint=false), and the description adds real substance: coin settlement, that a long's max loss equals the flat premium paid, and the full return field list including null-as-unbounded semantics. However the claim that long max profit is 'unbounded, dominated by the put leg's payoff as price falls toward zero' is internally inconsistent — downside put profit is bounded by the strike and the unbounded upside comes from the call leg — which weakens confidence in the disclosed behavior.

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-loads purpose, then definition, then risk/settlement behavior, then usage examples, then returns — a sensible priority order. It is dense and slightly long, and the flawed max-profit sentence costs space without earning it, but there is no filler.

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, the description correctly enumerates the return fields (combinedIntrinsicCoin, scenarioPnlCoin, scenarioPnlUsd, upper/lowerBreakevenPrice, maxLossCoin/maxProfitCoin, isStraddle, isProfitable), so an agent knows what comes back. All 8 params are documented in the schema and the strike/direction semantics are restated, leaving nothing critical missing.

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 the parameter-level baseline is 3, but the description adds meaning the schema does not carry: both legs must be the same direction and equally sized ('straddle/strangle units'), and premiums are per-contract in the base coin. This clarifies how the required params relate to one another beyond their individual descriptions.

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 precise verb+resource ('Payoff, P&L, and both breakeven prices for a long or short straddle/strangle at a scenario price') and disambiguates the two instruments definitionally (callStrike === putStrike vs callStrike > putStrike). An agent can separate it from siblings like run_options_payoff and run_spread_payoff without opening a 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?

Gives an explicit trigger ('Use when user asks about a straddle or strangle') plus two concrete example utterances covering the payoff and breakeven cases. It references run_options_payoff as the analogous coin-settled model, but never states when to prefer run_options_payoff or run_spread_payoff instead, so the routing is implied rather than fully specified.

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