Perpetual futures funding rates

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

With no annotations, the description carries the full burden. It does add real context by naming the three exchanges covered and by indicating the data is 'current' versus historical. It says nothing about update cadence, rate limits, or what happens for an untracked slug, so behavioral disclosure is only partial.

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 well-formed sentence with zero filler, front-loading the primary resource (current funding rates) before the secondary history mode. The parenthetical example is embedded efficiently rather than given its own sentence.

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?

For a one-optional-parameter read tool with no output schema, the description covers the resource, the sources, and both query modes, which is enough for correct invocation. It leaves the history window (how far back) unspecified, which is the only notable gap.

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% and the single 'slug' parameter is undocumented in the schema, so the description must compensate — and it largely does, giving the exact format with examples (btc, eth, sol) and clarifying that supplying it switches to single-symbol history. The one gap is that it never states the parameter is optional, though the dual-mode wording makes that inferable.

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 (perpetual funding rates) and enumerates the data sources (Binance, Bybit, OKX), so the agent knows exactly what data it gets. It also distinguishes two modes — cross-symbol current rates vs. single-symbol history. It does not explicitly contrast itself with the sibling crypto_market, which is the only thing keeping it from 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?

The 'current ... or one symbol's history by slug' construction implies how to choose between the two modes, which is useful routing guidance. However, there is no explicit statement of when to reach for this tool over crypto_market or any other sibling, and no exclusions or prerequisites are given.

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