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

Annotations already declare readOnlyHint, openWorldHint, and destructiveHint=false, so safety is covered. The description adds genuinely useful behavioral context beyond them: a $0.005 USDC x402 payment requirement and the fact that results are bounded to the queried block window. It stops short of describing pagination or result-size limits.

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 tight sentences, front-loaded with purpose, then scope and cost. Every sentence earns its place with no filler.

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 read-only query tool with full annotation coverage, the description covers purpose, filtering, block-window scope, and cost. With no output schema, it could say more about the shape of returned transfers or result limits, but nothing critical for correct invocation is missing.

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 description coverage is 100%, so token, from_block, to_block, from_address, and to_address are all documented in the schema. The description only restates the sender/recipient filtering, adding no format or default details beyond the structured data. Baseline 3 applies.

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 (Find), resource (ERC-20 Transfer events), and scope (on Base, optionally filtered by sender/recipient). This is distinguishable from generic siblings like base_logs or base_receipt without opening their 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?

Gives implied context via the block-window and filter framing, but never states when to prefer this over base_logs (generic log query) or other sibling tools, and offers no exclusions. Usage must be inferred.

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