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

Annotations declare readOnlyHint=false and destructiveHint=false, and the description proactively explains the unusual readOnlyHint=false ('not marked read-only because each call is charged') along with pricing and that failed calls are free. This resolves a genuine annotation ambiguity an agent would otherwise misread, though it doesn't cover rate limits or pagination beyond the 'up to 100 logs' 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 core action, then filters, return shape, routing guidance, and pricing in a tight sequence. Every sentence carries information, though the pricing/annotation-rationale tail makes it dense enough that a 4 is fairer than a 5.

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 compensates by describing the return shape ('up to 100 logs with block, transaction hash and topics') and the result cap. For a 3-param read tool with a clear sibling, nothing needed to call it correctly 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 coverage is 100%, so both optional parameters are already documented with ranges and format. The description restates the 1-1,000/default-50 range and clarifies topic0 is a 0x 32-byte signature hash, adding only marginal detail beyond the schema. Baseline 3 is appropriate.

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 ('List recent event logs a contract emitted on Base') and scopes it by block range and optional topic0 filter. It explicitly names the sibling it is not (base_receipt) for single-transaction outcomes, so an agent can route without opening either 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?

Gives concrete use cases ('watch transfers or contract events') and an explicit alternative with its selecting condition ('for one transaction's outcome use base_receipt'). The when-to-use and when-not-to-use are both spelled out.

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