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

With no annotations, the description carries the burden well: it discloses the full output shape, cache staleness (cache_age_s), error behavior (unknown coin → 400, not charged), and payment mechanism/price ($0.002 USDC via x402). It omits rate limits and latency expectations, which keeps it short of a 5.

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 purpose, then use case, then input/output contract, then error and pricing notes. Dense but every clause carries information; the output field list is long but necessary given no output schema.

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 single-parameter tool with no output schema and no annotations, the description covers input examples, return fields, staleness, error handling and cost. The only real omission is guidance on when to prefer hl_funding_screener over this single-market endpoint.

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 already 100%, so the bar is baseline 3. The description adds value by giving concrete example tickers (BTC, ETH, kPEPE) and restating the failure semantics for unlisted/delisted symbols, reinforcing what the schema says.

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 first sentence names the exact resource and scope: predicted funding comparison across Hyperliquid/Binance/Bybit for one perp market, plus funding rate, OI and basis. It is a specific compound verb+resource statement that an agent can match to a task immediately.

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 monitors a perp position or funding carry" gives a clear triggering context. It lacks an explicit exclusion or pointer to the sibling hl_funding_screener for multi-market screening, so the agent must infer single-market vs screener division.

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