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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds meaningful behavioral context by specifying the return components: gap, signal, and sample-size quality. It does not detail edge cases like what happens if both baseRateId and baseRateValue are supplied, but that is a minor gap.

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 first sentence is front-loaded with the core action and output. The enum list is somewhat redundant with the schema but still useful for discoverability, and the use-case sentence earns its place. Overall it is organized and not padded.

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 no output schema, the description compensates by naming the result fields (gap, signal, sample-size quality). Inputs are well covered by the schema, and the description clarifies the either/or relationship between baseRateId and baseRateValue. Minor ambiguity remains about conflict or omission behavior, but the tool is simple enough that the description is essentially complete.

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%, so the baseline is 3. The description repeats the enum list and the baseRateValue alternative but does not add new semantic meaning beyond the schema. No extra parameter guidance is provided, so it does not rise above 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 states a specific verb-resource pair ('Compare a market price against the historical base rate') and enumerates the outputs (gap in percentage points, signal, sample-size quality). It clearly differentiates this tool from siblings like calculate_ev or convert_probability by focusing on historical base-rate comparison.

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 explicit use-case phrasing ('how does this price compare to history', 'is the market ignoring the base rate', 'historical frequency vs market') and explains the two input paths (baseRateId or baseRateValue). It does not name alternatives or exclusion conditions, but the context is clear enough for an agent to select it appropriately.

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