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

No annotations are supplied, so the description carries the full behavioral burden and does very little with it. It does not state whether this is read-only, what time range or granularity the history covers, whether results are paginated or truncated, or how failures are reported — all material for calling it correctly.

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 short, front-loaded sentence with no filler, which is efficient. The brevity is close to under-specification rather than verbosity, so it does not earn a 5 but wastes nothing.

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 and no annotations, the description is the only place behavioral detail could live, and it omits the return shape, time coverage, and granularity of the funding history. The optional 'pair' parameter also leaves open what happens when it is omitted, which the description never addresses.

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 100% and the single 'pair' parameter is thoroughly documented in the schema, including QUOTE-FIRST keying, fuzzy form resolution, and the suggestion behavior. The description adds nothing beyond that, so the baseline 3 applies.

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 names a specific resource ('Historical funding rates') and a specific scope ('perpetual markets'), which is enough to tell it apart from siblings like everstrike_ohlcv or everstrike_trades. It stops short of explicitly naming those alternatives, so it lands at 4 rather than 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?

There is no when-to-use guidance at all: no mention of what window of history is returned, whether the pair is required to narrow results, or which sibling to use for current funding versus historical funding. The only cue is the implicit 'historical' framing, which an agent must infer.

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