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

Adds substantial context beyond annotations: return cap of 100 logs, fields returned, the pricing model ($0.003/call, first 25 free, failed calls free), and directly explains the unusual readOnlyHint=false ('not marked read-only because each call is charged'). That reconciliation of annotation and behavior is exactly what a good description should do. It does not, however, describe rate limits or pagination for the 100-log 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 purpose, scope and filter before the routing hint, which is the right ordering. Slightly heavy at the tail with a semicolon-chained payment/annotation rationale, though each clause carries real 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 covers the return shape (up to 100 logs with block, tx hash and topics), the query constraints, the alternative tool, and the billing semantics. An agent has everything needed to call it correctly and interpret the result.

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 baseline is 3, but the description upgrades the topic0 semantics by specifying it is a 0x 32-byte event signature hash rather than merely an 'event signature hash'. It also restates the blocks range and default, which is redundant with the schema rather than additive.

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 (List), resource (recent event logs), chain scope (Polygon PoS), and block window. It explicitly distinguishes itself from the sibling polygon_receipt, so an agent can select it 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 both the positive case ('use to watch transfers or contract events') and the exclusion with a named alternative ('for one transaction's outcome use polygon_receipt'). Nothing is left to inference.

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