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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, openWorld), and the description adds substantial context beyond that: data 'may be delayed or wrong', exact rate limit (100 calls/day per client), per-call price, prepaid batch size, and the payment-required handshake that yields a payment_token. That is exactly the operational behavior an agent needs to handle the paid path.

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 core capability, then intervals, then units, then the operating constraints — a sensible order. The boilerplate disclaimer ('Education/information only; not financial advice') is padding for an agent, but everything else earns its place.

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 7-parameter tool with no output schema, the description covers ordering, granularity, units, rate limits, and the full paid-retry flow. It does not describe the shape of each candle record, but OHLCV is a well-known format and the key semantics (ordering, units) are given.

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 86%, so the baseline is 3 and the schema already documents pool format, limit range, and timestamps. The description adds value the schema does not: it ties interval choices to candle granularity, clarifies that results are oldest-first (disambiguating start_time/end_time ordering), states volume is in the base asset, and explains the relationship between payment_token and payment_tx.

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?

Names the exact resource (OHLCV candles for a DeepBook pool), the ordering (oldest first), the supported intervals, and the volume denomination (base asset). This is unmistakably distinct from siblings like get_volume, get_recent_trades, and get_order_book, which return different data shapes.

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 guidance is implied through the payment flow: free 100 calls/day then 0.002 USDC, with payment_tx/payment_token required only after the free tier — that tells the agent when those params become relevant. However, the description never says when to prefer this over get_volume or get_recent_trades, so the alternative-selection guidance is absent.

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