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

Annotations already declare readOnlyHint and openWorldHint, so the read-only profile is covered. The description adds genuinely useful context beyond them: the archive is append-only, daily hashes are published and Bitcoin-timestamped (integrity/verifiability), and calls cost $0.05 USDC via x402 on Base or Solana — a payment/auth requirement an agent must know 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?

Two dense sentences, front-loaded with what the tool returns, followed by the constraint and pricing. No filler; every clause (range cap, filters, integrity, cost) 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 4-param read tool with no output schema, the description covers scope, filters, integrity, and payment. It stops short of describing what a returned event record contains or what the state enum values mean, which an agent would need to build a correct backtest query.

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 75% and the schema already documents from/to format and the 30-day cap; the description restates the range limit and that coin/state are optional filters, adding little new. The state enum's seven values (up_50pct_7d, funding_top5, etc.) are never explained in either the schema or the description, leaving their meaning unclear.

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: 'Signed historical crowd-state events for backtesting', with scope (up to 30 days per call) and filters (coin, state). It clearly reads as the historical/archive counterpart to siblings like crowd_states or crowd_market, though it never names a sibling to draw that distinction explicitly.

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?

The phrase 'for backtesting' implies the use case (retrieving past events rather than live state), but there is no explicit when-to-use vs. when-not, and no pointer to the sibling that serves current/live crowd state. Usage is inferable but not directed.

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