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

readOnlyHint=true already marks this as a read-only operation, and the description does not contradict that. The description adds useful output-oriented context (hits, direction, mean error), but it does not disclose behavioral details such as evaluation window, aggregation, or relationship to other prediction metrics. This is acceptable but minimal given the 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?

The description is a single, efficient sentence with a useful colon-separated list of the reported metrics. It has no filler and communicates the core purpose quickly, though it sacrifices some behavioral and comparative context for brevity.

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 description names key output concepts but there is no output schema, so the agent cannot infer the exact return shape, units, or evaluation period. The heavy overlap with sibling accuracy/performance tools is not addressed, though for a read-only tool with zero required parameters and well-documented filters, the description is minimally adequate.

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 100%, and each parameter already has meaningful documentation: kind has example values, symbol notes server-side canonicalization of GPW aliases, and universe states its default. The tool description adds no parameter-level meaning beyond the schema, so the baseline score of 3 applies.

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 identifies the resource (numerical price-movement prediction accuracy) and names three concrete metrics: hits, direction, and mean error. It is clear about what the tool reports, though it does not explicitly differentiate it from similar siblings like get_forecast_accuracy or get_ranking_performance.

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 gives no guidance on when to use this tool versus alternatives such as get_forecast_accuracy, get_my_alert_performance, or get_ranking_performance. The optional filters are present in the schema, but no scenario or exclusion criteria are described.

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