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

Annotations declare openWorldHint, idempotentHint and destructiveHint=false, so the safety profile is largely covered. The description adds genuinely new behavioral context the annotations do not: the exact cost (0.002500 USDC on Base mainnet), the settlement network, and the requirement to persist the private idempotencyKey for retries. The only mild tension is the word "Read" against readOnlyHint=false, but the disclosed payment explains that flag.

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?

Three short, front-loaded sentences with no filler: action, cost, and idempotency handling. Tight and well-ordered, though extremely terse given how little semantic content it carries.

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 paid RPC tool with no output schema, the description handles the payment/idempotency contract well but omits what the call returns (a block hash) and what the sole data parameter represents. An agent knows how to pay and retry but not what to pass or expect back.

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 50%: idempotencyKey is fully described in the schema, but the actual params array (a single 0..100000000 integer) has no description anywhere. The description says nothing about what that integer means (block height), so it fails to compensate for the coverage gap.

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?

"Read getblockhash from Bitcoin" restates the tool name with a generic verb rather than explaining what the method does (return the block hash for a given block height). It adds the chain identity, but an agent that does not already know the Bitcoin RPC name learns nothing about the purpose. No differentiation from siblings like bitcoin_getbestblockhash or bitcoin_getblockheader.

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 guidance on when to use this tool versus the many sibling block/header/hash methods. The description covers payment and idempotency mechanics, but nothing helps an agent choose this tool over bitcoin_getbestblockhash or bitcoin_getblockheader.

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