historical_price

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

No annotations exist, so the description carries the burden. It adds the key modal behavior: a point-in-time snapshot versus a range chart via the 'or' relationship, and mentions the investment snapshot. However, it does not describe response shape, error behavior, or what happens if both date and days are supplied.

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?

One compact sentence with the main resource and usage modes front-loaded. It is easily scannable, though the incomplete days list slightly reduces precision.

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?

At 60% schema coverage with no output schema or annotations, the description should explain the two modes' selection rules, defaults, and response expectations. It omits the required coin parameter, the meaning of vs_currency, and the mutual exclusivity of date versus days.

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?

The schema already documents date, days, and investment; the description adds no new meaning and actually lists a subset of valid days, omitting 14 and 180. It gives no help for the undocumented coin and vs_currency parameters.

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?

States a specific resource ('historical price') with two explicit modes: a point-in-time date with investment snapshot, or a range chart by days. It is easily distinguishable from sibling get_price by the word 'historical,' though it does not name the alternative.

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?

No guidance is given on when to use this tool instead of get_price or other siblings. The historical prefix only implies the use case, and there are no conditions or exclusions for choosing between the date and days modes.

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