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

Annotations already establish readOnlyHint=true, openWorldHint=false and idempotentHint=true, so the safety profile is covered. The description adds a genuinely useful behavioral fact not present in structured fields: the cost per call (1000 sats or US$0.8 USDC) and that the output is JSON, which matters for an agent deciding whether to spend.

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?

Two tight sentences: the substantive content listing comes first and the commercial terms second, with no filler. Front-loading is correct and every clause carries information, though the report-content enumeration is dense rather than elegant.

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 read-only report tool with no output schema, the description adequately conveys what is returned and what it costs. The date range and payment-token mechanics live in the schema, and the price lives in the description, so the two together are sufficient for a correct call.

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%, and each parameter (date, l402, pay_with) is documented in the schema itself, including the 90-day window and the '<token>:<preimage>' format. The description adds no parameter-level detail beyond what the schema provides, so the baseline 3 is appropriate.

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 names a specific resource (a one-day report) and enumerates its contents: whale flows vs world news, lagged correlations, laundering patterns, headlines, analyst brief. This is far more concrete than a generic 'report' tool. It does not explicitly differentiate from siblings like bitcoin_market_pulse, but the enumerated content makes its scope inferable.

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?

There is no explicit when-to-use or when-not-to-use guidance, and no sibling is named as an alternative for adjacent needs (e.g., bitcoin_market_pulse for price data). The only contextual clue is the pricing line, which implies a paid, deliberate call rather than routine use.

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