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

Annotations only cover readOnly/openWorld/idempotent, while the description adds the genuinely scarce information: every call is charged in USDC from a configured wallet, spending is bounded by budget caps, and results are third-party data rather than instructions. This is exactly the cost, constraint, and trust context an agent needs before invoking.

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 the paid/budget warning, then a compact product table with prices, params, and data provenance. Dense but every line carries selection-relevant information; the '+' bullet style is slightly terse rather than wasteful.

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?

With no output schema, the description partially covers returns by naming the data source and shape ('latest crypto trade tick', 'bundle of all cached live crypto quotes'), and it documents nested params per product. It omits error/empty-result behavior and per-product rate limits, which keeps it out of 5 territory.

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 100%, so the baseline is 3, but the description goes further by mapping which params belong to which product ('params symbol*' vs 'params symbols') — essential since the schema's params object is free-form with additionalProperties. The confirm_over_cap semantics live only in the schema, not the description.

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+resource ('Crypto asset price quotes') and enumerates the two concrete products with their underlying data sources (Binance trade tick cache vs market scraper bundle). It does not differentiate itself from siblings like get_price_quote or call_product, so it stops short of 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?

Gives clear selection logic between its own products (single symbol* for market.quote, plural symbols for the bundle) and states the payment prerequisite up front. It never says when to prefer this tool over sibling quote tools such as get_price_quote, so no explicit alternatives for the agent.

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