betr_market_movers

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

Annotations already declare readOnlyHint, openWorldHint, and idempotentHint, so the safety profile is clear. The description adds the return structure and explicitly states 'Auth: none needed', which is useful beyond the annotations. It doesn't contradict annotations and provides concrete output shape.

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 extremely concise: one line explaining the purpose and one line with the return structure. Every word earns its place, and key facts are front-loaded.

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 parameterless, read-only tool with strong annotations and a return schema described inline, this is fully complete. The description covers what it returns and authentication requirements, leaving no ambiguity.

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?

There are zero parameters, and the schema is empty with 100% coverage. Baseline for zero parameters is 4; the description doesn't need to explain parameters since there are none. It correctly focuses on output.

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 clearly states it provides 'Racing market movers' — runners whose fixed prices are shortening/drifting. This is a specific, actionable purpose with a clear resource (racing market movers) and distinguishes itself from siblings like betr_race or betr_race_flucs by focusing on price movements.

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 implies usage: if you need racing market movers, use this tool. However, it does not explicitly state when to use this versus alternatives like betr_race_flucs or betr_next5_races, nor does it mention any exclusions or context where it's not appropriate.

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