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

Beyond the readOnly/openWorld/idempotent annotations, the description discloses material behavior: plans are deterministic synthetic templates, and fills, stop/target ordering, MAE/MFE, and outcomes are settled on later historical candles with costs. It also warns that analogues are not proof of an edge. This adds genuine context rather than restating 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?

Three sentences with no filler: primary action, behavioral mechanics, and usage caveat. The main verb and resource are front-loaded, and every sentence earns its place.

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 13-parameter tool with no output schema, the description captures the purpose, output concepts (fills, MAE/MFE, outcomes), and important caveats, while annotations cover safety and idempotency. It does not explicitly state that all parameters are optional or how defaults tie to the current chart state, but the schema and parameter defaults fill most of that gap. Strong but not exhaustive.

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 69%, and many parameters are already described well (bars, limit, feeBps, symbols, timeframe). The description adds conceptual framing around "current market state" and "costs" that helps make sense of ref, symbol, timeframe, feeBps, and slippageBps. However, it does not compensate for the undescribed enum parameters like side, setup, market, and exchange, so the added parameter-level value is only moderate.

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 opens with a specific verb and resource: "Retrieve compact historical trade analogues for the current market state." It further clarifies the mechanism with "deterministic synthetic templates" and later-candle settlement, which clearly separates it from sibling tools like backtest_run or screener_backtest. This is a precise, non-tautological purpose statement.

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?

"Use it to compare similar wins and failures, never as proof of an edge" provides a clear use case and a when-not caution. It does not name alternative sibling tools or specify when to prefer backtest_run or strategy_research, so it falls short of a 5. Still, the guidance is explicit enough to shape correct usage.

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