cmc_cmc20_historical

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

No annotations are provided, so the description carries the full burden. It implies a read-only historical lookup but says nothing about rate limits, whether the index series can be sparse, how far back history goes, or what 'provider-supported' actually restricts — meaningful gaps for a market-data tool.

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?

A single efficient sentence with the resource front-loaded and no padding. It is well-sized, though it is concise at the cost of the detail an agent would need.

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?

An output schema exists, so return values need not be explained, but with zero annotation coverage, zero parameter descriptions, and no usage guidance, the definition is under-specified for a four-parameter historical data tool.

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 0% across four parameters, and the description only gestures at one of them ('interval'). count, time_start, and time_end — including their accepted formats — are entirely undocumented in both the schema and the description.

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 ('Get') and resource ('historical CoinMarketCap 20 Index values'), which cleanly separates it from cmc_cmc20_latest and the other *_historical siblings. It stops short of explicitly naming those alternatives, but the 'historical' qualifier plus the tool name make the target unambiguous.

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 when-to-use guidance, no mention of prerequisites, and no routing to the sibling tools (e.g. cmc_cmc20_latest for current values). The only contextual hint is 'provider-supported interval', which is a constraint rather than usage guidance.

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