defillama_get_historical_prices

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It states the core behavior (fetching historical prices) but reveals nothing about the format of coins, the timestamp unit, possible limitations, rate limits, or what the response looks like. This is minimal transparency beyond the bare functionality.

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 one short sentence, with no fluff and front-loaded information. However, it is under-specified, missing essential context about the parameters and expected behavior. This is acceptable conciseness for a simple sentence but not enough to earn a higher score.

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 the tool has two required parameters, no output schema, and no annotations, the description is incomplete. It does not explain the coin identifier format, timestamp semantics, return structure, or error scenarios. A user would need significant external knowledge to invoke this tool correctly.

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 input schema has two parameters ('coins' as an array of strings and 'timestamp' as a number) with 0% schema description coverage. The tool description does not mention either parameter or add any meaning to them. It does not explain what 'coins' should look like (e.g., chain:address format) or what 'timestamp' represents (e.g., Unix seconds).

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 'Get historical prices of tokens' uses a specific verb ('get') and resource ('historical prices of tokens'), clearly distinguishing it from the sibling tool 'defillama_get_token_prices' which presumably returns current prices. However, it does not explicitly mention alternatives, so it stops short of a 5.

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 usage guidance is provided. The description does not indicate when to use this tool over the sibling 'defillama_get_token_prices' or any other tool, nor does it mention any prerequisites or constraints. The only implicit signal is the word 'historical' in the name and description, but this is not sufficient guidance.

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