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

Annotations already cover read-only, idempotent, and non-destructive behavior. The description adds useful context by clarifying that from/to are Unix seconds while response timestamps are milliseconds, and by detailing the returned series fields. This goes beyond the annotations without repeating them.

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 compact and front-loaded, with the core purpose stated first, followed by necessary unit details, return format, and alternatives. Every sentence contributes value without redundancy.

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 an output schema exists and annotations cover the safety profile, the description covers all essential invocation details: identification method, time units, response fields, and alternatives. No critical gaps remain, though it could mention pagination or limits if any, but none appear relevant.

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 provides 100% coverage with descriptions and examples for every parameter, so the description does not need to add much. It does reinforce that `id` is the asset platform and `contract_address` is the token, but this information is already present in the schema. Baseline 3 is appropriate.

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 the tool fetches historical series between two specified time points for a token identified by contract address. It uses specific verbs and resources, and differentiates itself from the sibling tools such as get_coingecko_token_market_chart and get_coingecko_coins_id_market_chart_range.

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?

Explicitly states when to use this tool: 'when you have an address and a fixed window.' It also names two alternatives and their use cases, providing clear routing guidance for an agent.

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