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

Annotations already establish read-only, non-destructive behavior, so the description adds meaningful extra context: it explains the output set and, importantly, that a verdict of insufficient evidence is intended rather than a failure. This warns the agent about a likely outcome without contradicting any annotation.

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 well-structured sentences front-load the purpose, then cover return values, usage triggers, and expected behavior. There is no filler 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?

Given a rich schema, annotations, and an output schema, the description supplies everything an agent needs to decide when to call this tool and what to expect: purpose, outputs, usage cue, and a warning about the thin-evidence verdict. No important calling context is missing.

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 80%, so the schema already documents most parameters in detail. The description reinforces the statistical interpretation of the tool but does not add new meaning to individual parameters like confidence, benchmarkSharpe, or trialSharpes, which justifies the baseline score of 3.

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: it answers whether a strategy's measured performance is distinguishable from luck. It names concrete outputs (Probabilistic Sharpe Ratio, bootstrap confidence interval, Minimum Track Record Length) that make it clearly distinct from the factor, regime, and self-attack sibling tools.

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?

It gives an explicit trigger condition: use it whenever someone quotes a Sharpe ratio, win rate, or return and you need to know whether the number means anything. It does not name alternative tools or state when not to use it, so it stops short of a full 5.

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