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

With no annotations, the description carries the full burden; it does valuable work by disclosing the paid model ('Costs $0.005 USDC on Base via x402'), which matters before invocation. However, it says nothing about failure behavior for an invalid or unfound hash, latency, or whether the transfer decoding is best-effort for non-ERC20 calls.

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?

Two sentences, zero filler: the content enumeration comes first, the cost caveat second. Every clause maps to something an agent needs before calling.

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?

A one-parameter read tool with no output schema, so the prose return-value inventory is doing real work and it is thorough. Near-complete; only error/edge behavior is unaddressed.

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?

Single parameter with 100% schema description coverage and an explicit 0x+64-hex pattern, so the schema already defines the input fully. The description adds no format detail or constraint beyond it — baseline 3 for a fully documented 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 ('Human-readable summary of a Polygon PoS transaction') and enumerates exactly what the summary contains: status, block and time, sender/recipient, value, gas, method selector, decoded ERC-20 transfers. The chain qualifier cleanly separates it from the eth_/base_/arbitrum_/optimism_transaction_summary siblings.

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?

Usage is implied — you have a Polygon transaction hash and want a decoded overview — but there is no explicit when-to-use guidance, no exclusions, and no pointer to alternatives (e.g., polygon_token_snapshot or raw RPC). The agent must infer the selection context.

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