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

Annotations already cover read-only and idempotent semantics, and the description adds the non-obvious fact that the result carries a signed receipt. It stops short of explaining what that receipt attests to, whether pending blocks behave differently, or any failure modes — real value, but thin.

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 sentences, no filler, with the chain identity and field list front-loaded before the receipt note. Every clause carries information an agent could not get from the title alone.

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?

Output schema is present, so return-value detail is unnecessary, and the input is a single documented optional parameter. The only remaining gap is the vague 'signed receipt' reference, whose purpose for the caller is never made actionable.

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?

The single 'block' parameter has 100% schema coverage including hex/decimal/tag formats and the 'latest' default, so the schema does the heavy lifting. The description adds nothing beyond 'any block', which is the expected baseline when coverage is high.

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?

Names the specific chain (Base, 8453) and enumerates the exact fields returned (number, timestamp, tx count, base fee), which separates it from transaction-level siblings like tx_activity. It does not explicitly contrast itself with any sibling, but the resource is unambiguous.

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?

No statement of when to reach for this versus erc20_balance, tx_activity, or receipt_verify. 'For any block' only restates the input flexibility rather than giving selection guidance or exclusions such as 'use tx_activity for per-transaction data'.

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