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

Annotations cover readOnlyHint and openWorldHint, and the description adds genuinely useful context beyond them: the exact set of metrics recomputed, the MATCH/MISMATCH return shape, and a payment requirement ($0.01 USDC via x402 on Base) which is important invocation context. It omits behavioral details like how tolerance_pct affects MATCH decisions, holding it back from a 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?

Three tight sentences, front-loaded with the core action and metrics, then the return format, then cost. No filler; the only minor question is whether the pricing sentence belongs in the description, but it is legitimately useful.

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?

The readOnly annotation covers safety and the description usefully describes the return values in lieu of an output schema. However, with 7 undocumented parameters (including nested trades/claimed objects and behavioral knobs like tolerance_pct and initial_capital), an agent cannot confidently invoke this correctly from the definition alone.

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 0% across 7 parameters, so the description carries the full burden. It only touches the trade input ('trade list (CSV or JSON)') and the claimed numbers, leaving commission, tolerance_pct, initial_capital, single_position, and the trades/claimed structure completely undefined. The compensation is far short of what 0% coverage demands.

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 specific verbs (recompute, compare) and the exact resource (net profit, win rate, profit factor, max drawdown, trade count from a trade list). An agent immediately understands it is a reconciliation/verification tool rather than a backtest runner. Siblings are unrelated, so no differentiation is needed.

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 implies the usage context (checking a claimed backtest against a trade list) but never states when to use it versus alternatives or any prerequisites. There are no exclusions or competing tools named, leaving usage to inference.

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