Probability of Profit

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

Annotations already provide readOnlyHint=true, which covers the safety profile. The description adds a meaningful behavioral detail: it uses N(d2)-based probabilities on the combined position payoff, which gives the agent context about the calculation method. It also states the return format ('Probability of profit percentage'). No contradiction with 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?

The description is well-organized with a purpose statement, method note, usage bullet list, args list, and returns section. The example JSON is useful but adds length. Every section contributes meaningfully, and the structure makes it easy to scan. It is appropriately concise for the complexity.

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 calculation tool with no output schema, the description adequately covers inputs, the method, and the return value. It does not describe edge cases or assumptions (e.g., day-count convention, validity of legs), but these are not critical for the tool's primary function. The description is sufficient for an agent to 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 0%, so the description must compensate. It does so effectively for the `legs` parameter by providing a JSON example and clarifying that 'iv accepts percent or decimal; premium is per share'. The other parameters are briefly described (current stock price, days to expiration), but without additional unit or format details. Overall, it adds significant value beyond the raw schema.

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 clearly states 'Calculate the probability of profit for a set of option legs' with a specific verb and resource. It distinguishes itself from sibling tools like calculate_expected_move by focusing on PoP, and further clarifies use cases via the bullet 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?

The description explicitly enumerates when to use the tool ('when the user asks about Probability of profit / PoP for a trade' and 'Odds a spread or condor expires profitable'). It does not mention when not to use it or point to alternatives, which would push it to a 5.

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