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

No annotations exist, so the description carries the full burden and does so: it states what the score predicts and does not predict, warns that a low score is weak evidence (a 0.5 cutoff recovers under half of runs that did trade), and discloses cost and auth (0.02 USDC via x402 or API key, free for key clients). It also flags the prohibited downstream use ('Never tell someone their strategy will not trade because this scored it low').

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-loaded with the verb, resource and purpose before the caveats, and the pricing note is bracketed at the end. It is long and repeats the 'low score is not proof' warning twice in different words, but the repetition is defensible given how easy that misuse is.

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, no annotations, and a nested-object parameter, the description supplies what the schema omits: candidate structure, the 99-cap, the signal_type prohibition, score interpretation and its limits, and access/pricing. An agent has everything needed to call it and to report results honestly.

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 baseline is 3; the description adds real constraint beyond the schema by stating 'one asset and up to 99 candidates', showing the candidate shape as {entry: [...], exit: [...]}, and warning 'the roles come from the library, so do not pass signal_type' — guidance not derivable from the generic object-typed items 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?

States a specific verb and resource with scope: 'Rank several candidate strategies by how likely each is to trade at all, before spending backtests on them.' It also explicitly separates the tool from backtesting ('IT PREDICTS WHETHER A STRATEGY WILL PLACE TRADES, AND NOTHING ABOUT WHETHER IT WILL MAKE MONEY: only a backtest answers that'), which distinguishes it from run_backtest and evaluate_strategy.

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 explicit when-to-use ('Use it to choose which of many candidates to backtest first'), when-not-to-use ('never as a verdict on a single strategy'), and names the alternative activity that answers the other question (backtesting). The minimum candidate count and the 'ranking is the answer, not an individual probability' rule are also stated.

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