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

With no annotations, the description carries full disclosure and does add valuable traits: a paid request ($0.005 USDC on Base via x402) and a refresh/polling pattern. These are non-obvious behaviors an agent must know before invoking. It still omits error behavior, rate limits, and auth mechanics, but the payment disclosure is significant.

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?

Three sentences, front-loaded with the resource and purpose, then usage, then cost. Tight overall, though 'designed for recurring refresh' and 'poll again when the selected candle interval advances' are somewhat redundant.

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?

No annotations and no output schema, so the description must stand alone; it covers resource, granularity range, cost, and refresh pattern adequately for a market-data fetch. It could say more about the returned OHLCV fields since no output schema exists, but the tool name and resource term carry most of that.

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 80%, so the schema already documents most parameters, establishing a baseline of 3. The description's 'Supports 1m–1d bars' loosely maps to the granularity enum (60–86400), adding minor value, but it names no parameters or formats beyond that.

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?

States a specific verb-like resource (OHLCV candles) clearly: 'Crypto OHLCV candles for autonomous trading and indicator pipelines.' This tells an agent exactly what data it returns. However, it does not differentiate from siblings like canonical-crypto-ohlcv or crypto-24h-stats, which an agent comparing closely-named tools would need.

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?

Provides implied usage guidance: 'for autonomous trading and indicator pipelines' and 'designed for recurring refresh; poll again when the selected candle interval advances.' This gives a polling cadence but names no alternative tools and no when-not-to-use conditions, leaving selection between this and canonical-crypto-ohlcv to inference.

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