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

Annotations already declare a read-only, non-destructive, closed-world calculation, and the description adds real behavioral context beyond that: commission is per standard lot in the quote currency and the commission-in-pips result is independent of position size by construction. It also previews the return shape. Does not discuss error cases or assumptions on spread handling, keeping it below 5.

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 the definition, then the domain nuance, then a 'Returns:' list. The commission-scaling sentence is dense but earns its place by explaining why the pip figure is size-independent. Slightly overpacked but 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?

No output schema exists, so the description compensates by naming the returned fields (pipSize, commissionPips, totalCostPips, breakevenPrice). Inputs are adequately framed. Complete enough to call correctly, though edge cases (e.g. missing commission default behavior) are only implied.

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?

With 60% schema coverage, the description usefully explains the semantics of commissionPerLotRoundTrip (per standard lot, pair's quote currency, default of 0 implied) and how it interacts with lot size. It adds meaning over the bare schema. Schema already documents pair, spreadPips, and the side enum, so it does not need to repeat those.

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+resource: computes forex breakeven price accounting for spread and round-trip commission, quantified in pips and price. This clearly separates it from generic computation siblings, though it never names a specific sibling (e.g. run_forex_pip_value or run_breakeven_planning) to disambiguate.

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?

Provides an explicit trigger: 'Use when user asks where's my true breakeven after spread and commission?'. This is clear usage context, but there are no exclusions or stated alternatives among the many run_forex_* / breakeven siblings.

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