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

Annotations already cover safety (readOnlyHint=true, idempotentHint=true, openWorldHint=true), so the burden is lowered. The description adds the crucial scope (28-day lookback, weekly transfer counts + distinct participants), an output-vocabulary, and payment behavior (x402 on Base, prepaid x-headers, 1 free call/day, no API key). It does not, however, describe return structure, rate limits, or edge cases (e.g., very new tokens), so it sits at a 3.

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?

The description is long and absorbs unrelated material — pricing, x402 payment instructions, free-call quota, 'Not financial advice.' For an agent selecting a tool, this dilutes the signal. Sentences are hard-hitting early but the tail is logistics (payments) that belongs in a payment/context field, not in the core purpose statement.

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-address, read-only analytic with an output schema present, the description supplies the missing conceptual frame (adoption trajectory vs. price, five output labels, 28-day window) that an agent needs to interpret the result. It omits the exact return structure, which is fine because an output schema exists, and it omits error/threshold semantics for the low_activity bin. Close to complete.

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?

Only one parameter (address), schema coverage is 100% and the description restates 'Required input: address', which is redundant with the schema. Because the schema already fully documents the parameter, baseline is 3; the description's added value is elsewhere (output labels, payment model), so a 4 rather than 5 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 analytic — reads weekly transfer counts and distinct participants over 28 days and classifies adoption trajectory into five states. It explicitly distinguishes itself from token-age (birth timestamp) and holder-distribution (static snapshot), and names the concrete output labels. Only the specific parameter/return shape keeps it from a clean 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?

It draws a sharp line versus price-oriented siblings (token_momentum, wash_trading) and against static-holder siblings (token_age), and explicitly tells the agent to pair with wash-trading. Strong routing. No explicit 'when NOT to use' for the analytic-vs-snapshot class beyond the sibling contrasts, so not a clean 5.

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