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

Adds substantial context beyond annotations: pricing ($0.003/call via x402 USDC or card key), the free tier, that failed calls are free, and that unknown hashes return 404 uncharged. Critically, it reconciles the unusual readOnlyHint=false by explaining 'Reads or computes only; not marked read-only because each call is charged.'

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-loaded with purpose and returned fields, then routing, then input, then pricing. Dense and every sentence carries information, though the pricing/credit sentence is slightly packed and could be separated.

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?

No output schema exists, but the description enumerates the returned fields (sender, recipient, value in POL, nonce, gas limit, function selector, block), so an agent knows what it gets back. For a single-param lookup this is complete.

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 description is not required to document the parameter. It nonetheless restates the 0x-prefixed 64-hex format and adds a concrete example hash plus the 404-on-unknown behavior, which adds modest value beyond 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+resource (look up a Polygon PoS transaction by hash) and enumerates the returned fields. Explicitly distinguishes itself from polygon_receipt and polygon_logs, so an agent can route correctly without reading 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 explicit when-to-use ('see what was sent or whether it exists') and names the two alternatives with the exact condition that selects each ('for success or failure and fees paid use polygon_receipt, for emitted events polygon_logs'). Also covers the unknown-hash case (404, uncharged).

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