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

With no annotations, the description carries the full burden, and it does disclose real behavior: derived statistics rather than advice, fees and risk ignored, and a paid call at $0.003 USDC (Base or Solana) via x402. It does not cover rate limits, latency, caching, or what happens on partial venue failures, so the behavioral picture is helpful but incomplete for a paid external API call.

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 trigger condition is front-loaded in the first clause, followed by input, output, caveats, and an example in a compact flow. The x402 pricing snippet tacked onto the example sentence is slightly awkward but still earns its place by signaling a paid call.

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?

There is no output schema, so the description must enumerate returns, and it does: per-venue mark, index/oracle, premium %, annualized funding, OI USD, plus max-min funding spread and ranked carry pairs. Missing only edge-case handling beyond the 404-not-charged note already in the schema.

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%, so both the coin symbol and the comma-list venues enum are already documented in the schema, and the description only restates 'Input: coin, optional venues' plus a ?coin=BTC example. Baseline 3 is appropriate since the schema does the semantic work.

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 states a specific analysis (perp basis: mark vs index premium, annualized funding, funding spread, carry pairs) over an enumerated venue set (Hyperliquid, dYdX v4, GMX v2, Lighter, Paradex; explicitly no CEX) for a single coin. That scope cleanly separates it from the broader siblings crypto_perp_funding and crypto_perp_screener, though it never names them outright.

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?

'Use when an agent compares one coin's perp basis on DEX venues only ... no CEX' gives a clear triggering context and an explicit exclusion. It stops short of naming the alternative tools (e.g. crypto_perp_funding for single-venue funding history) that an agent should pick instead when it wants CEX or multi-coin data.

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