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

Annotations already declare readOnlyHint=true and openWorldHint=true; the description adds genuinely new behavior: cost of $0.002 USDC per successful call via x402 on Base/Solana/Arc, and that failed calls are not charged. That payment/auth context is exactly the kind of information annotations cannot convey. It does not mention result ordering or recency guarantees, which keeps it from a 5.

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-loads the core purpose and returned fields, then groups alternatives and pricing into two coherent clauses; every sentence carries information. The 'for a different need:' colon-chain phrasing is slightly clunky but costs little and could be trimmed into a cleaner list.

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?

An output schema exists, so return values need no explanation, and the description still names the returned fields. It covers the one input parameter, names the closest alternatives, and discloses payment terms — everything an agent needs to select and invoke this paid read tool correctly.

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 100% and the single 'count' parameter already documents the 1-144 range and a default of 5; the description only restates the range. No additional semantics (e.g., what count=144 means in time span, or behavior when the chain has fewer blocks) are added, so this sits at the baseline.

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 operation and resource (most recent Kaspa blocks) plus the exact fields returned: hash, timestamp, blue score, DAA score, tx count, selected-chain status. It explicitly distinguishes itself from crypto_kaspa_block (single detailed block by hash) and crypto_kaspa_chain_color (blue/red counts), so an agent can pick correctly without opening schemas.

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 explicit alternative routing: use crypto_kaspa_block for a single block by 64-char hex hash, and crypto_kaspa_chain_color for merge-set blue/red counts. It does not cover other plausible Kaspa siblings such as crypto_kaspa_dag_state or crypto_kaspa_throughput, so the coverage is strong but not exhaustive.

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