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

The only annotation is readOnlyHint: true, which the description does not add to. It does not disclose what data is returned, whether rankings are historical or current, any assumptions, or potential limitations. For a read-only operation, the description adds minimal behavioral context beyond 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 vague sentence. While it is concise in length, it is under-specified and does not adequately convey the tool's purpose. It fails to earn its place by providing any actionable information for the agent.

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 only one parameter, no output schema, and a readOnlyHint annotation, the description still leaves critical gaps: what is the ranking? How is performance measured? What does the output look like? The tool is incomplete for an agent to understand its full behavior without additional information.

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% for the single parameter horizonDays, which is fully documented in the schema with type, default, range, and meaning. The description itself mentions no parameters, so it adds no value beyond the schema. Per the rubric, with high coverage, baseline is 3, and the description does not exceed baseline.

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 'Jak ranking sprawdzał się w przeszłości' (How the ranking performed in the past) indicates the tool is about historical performance of a ranking, but it is vague. It doesn't specify which ranking, what metrics, or how it differs from siblings like get_stock_rankings or get_signal_prediction_performance. The verb 'sprawdzał się' (performed) is imprecise and does not clearly establish the resource.

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?

There is no guidance on when to use this tool vs. alternatives. No context about what kind of ranking, what use case it serves, or any exclusions. The description provides no situational cues, leaving the agent without direction on when this tool is appropriate compared to the many similar 'get_*' siblings.

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