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

Goes well beyond the annotations by disclosing chain-specific behavior: no base fee so gas price is the whole per-gas price, no type-2 transactions, calldata truncated at 2048 bytes, decode provenance ('verified' vs 'standard' guess), a warning that decoded strings are untrusted, and that pending transactions have no block. These are exactly the caveats an agent needs and none are in the annotations.

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?

The identity of the tool and its result shape are front-loaded, and the routing sentence is placed last where it belongs. The field enumeration is dense and long but nearly every clause carries real information; it stops just short of being wasteful.

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?

There is no output schema, so the description must describe return values, and it does thoroughly: field list, nullability for pending txs, calldata truncation, and decode source semantics. An agent has everything needed to interpret the response.

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?

Only one parameter with 100% schema description coverage ('0x-prefixed 32 bytes'), so the schema already carries the semantics. The description reinforces that lookup is by hash but adds no format or syntax detail beyond the schema — baseline 3 for a fully documented single param.

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 ('a transaction by hash') and then enumerates the exact fields returned (block, position, from, to, value, gas, nonce, type, calldata). It explicitly distinguishes itself from get_receipt, so an agent can route between them 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?

Ends with an explicit alternative and the condition that selects it: 'Use get_receipt for status, gas used, fee and events.' This is clear routing guidance, though it only covers one sibling (not explorer_transactions or get_block) and offers no explicit exclusions for the rest.

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