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

Annotations already establish read-only, idempotent, non-destructive behavior, so the description correctly focuses on data semantics instead: both series come from the same venue snapshot row, giving a temporal-consistency guarantee a caller would otherwise not know. It also pins down units precisely (hourly decimal fraction for funding, base-asset coin count for OI, not USD notional), which prevents a common misinterpretation.

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?

Front-loaded with the purpose, then units, then a doc pointer — a sensible order with little waste. Minor redundancy in 'configurable lookback window, sampled at a configurable resolution,' which restates the schema's window and resolution parameters.

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?

With no output schema, the description carries the burden of explaining return values and does so for units and cross-series consistency. It stops short of describing the row shape (e.g. whether each sample carries a timestamp), leaving a small gap for a time-series 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 coverage is 100% and the schema already documents symbol, asset_id exclusivity, and the resolution constraint, so the baseline of 3 applies. The description adds only a pointer to external docs for window/resolution formats rather than restating or enriching parameter semantics itself.

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 verb+resource: 'Get perp funding rate and open interest history,' naming the exact two series returned. This is clearly distinguishable from siblings like get_price_history, get_volume_history, and get_candles, which cover different metrics.

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?

Usage is only implied by the resource itself (derivatives metrics rather than spot prices); there is no explicit statement of when to prefer this over get_candles or get_price_history. The symbol/asset_id mutual exclusivity is a calling constraint, not alternative-tool guidance, and is already documented in the schema.

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