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

Beyond the annotations (readOnly, idempotent, non-destructive), the description discloses the pricing/authorization model: 25 free calls per day, then $0.01 USDC per call via x402. That is the kind of thing an agent cannot get from structured fields and needs before calling.

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 trigger condition, then the result, then examples and cost — a sensible ordering with little waste. The closing 'Outputs explained: GET /api/tools/tx_version' is a slightly awkward pointer but short.

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 still tells the agent what the answer contains (version classification and compatible readers) and notes cost/auth. Minor gap: it defers output detail to an external URL instead of stating the response shape, and doesn't explain network-specific differences.

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; the description adds call-shape examples showing the tx vs tx_id alternatives in concrete form. It adds modest value over the schema's existing 'Give this or tx_id' wording rather than deep semantics.

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: it reports whether a transaction is legacy, version 0, or version 1, and which readers can decode it. That is easily separable from siblings like check_tx, explain_tx, and why_failed, which diagnose status rather than transaction format/version compatibility.

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 triggering conditions: when code can't find or read an on-chain transaction, or before relying on code that reads other people's transactions. It doesn't name a sibling alternative directly, so the exclusion boundary is inferred rather than stated.

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