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

Annotations already declare openWorldHint=true, destructiveHint=false, idempotentHint=false and, importantly, readOnlyHint=false; the description adds the reason for that non-obvious flag ('not marked read-only because each call is charged') plus pricing, free-failure behavior and the return shape. That is real value beyond the annotations, though it stops short of describing pagination, log ordering, or reorg/confirmation semantics.

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 purpose and scope, then the alternative, then cost/auth and safety rationale. Every sentence carries distinct information with no redundancy.

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?

Covers what an agent needs to call it correctly and interpret the result: filter semantics, return cap, per-call cost, payment methods, free-failure behavior, and why the read-only hint is false. No output schema exists, but the return contents are summarized.

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% and every parameter already carries a description, so the schema does the heavy lifting. The description adds only marginal meaning (topic0 as a 32-byte signature hash, the 1-1,000 block bound and default 50), which largely restates the schema.

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 Ethereum') plus the scoping mechanism (last N blocks, topic0 filter). An agent can distinguish this from eth_receipt and the per-chain *_logs siblings without opening the 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 positive usage ('watch transfers or contract events') and an explicit alternative with its selecting condition ('for one transaction's outcome use eth_receipt'). The filtering condition for topic0 is also implied in context.

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