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

Goes beyond annotations by disclosing cost and billing mechanics ('$0.01/call via x402 USDC or a card key', 'first 25 free', 'failed calls free') which gives real meaning to idempotentHint=false — retries are not free. It also caps the return at 100 logs and names the return fields, though it doesn't discuss pagination or how to reach logs beyond that cap.

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 eth_getLogs equivalent and the block window, then usage, then return shape, then pricing — a sensible order. It is somewhat dense and repeats the 1-1,000/default-50 detail already in the schema, but almost every sentence carries actionable information.

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?

With no output schema, the description steps in by naming the returned fields ('block, transaction hash and topics') and the 100-log ceiling, and it covers cost and safety. What's left implicit is behavior at the 100-log cap and whether results are ordered, which matter slightly for a log-scanning tool.

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%, so the schema already documents all three parameters and the baseline applies. The description restates the block range and default and clarifies topic0 as a '0x 32-byte event signature hash', which is only marginally more than the schema's own wording; the example address shows form but not what the address must be.

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 and resource ('Recent contract event logs on Base (eth_getLogs)') plus the exact scope: events a contract emitted over the last N blocks. It also distinguishes itself from base_receipt by name, so an agent can separate the two without opening a schema.

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?

Explicitly says what to use it for ('watch transfers or contract events') and redirects to the correct sibling for a different need ('for one transaction's outcome use base_receipt'). The when-not is stated, not implied.

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