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

With no annotations, the description carries the full burden. It usefully discloses the backing method (eth_getTransactionByHash) and that data is 'live from Base mainnet', which tells the agent this is a fresh read rather than cached. However, it says nothing about behavior for an unknown hash, hash format expectations, or rate limits.

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?

A single dense sentence with the resource and lookup key front-loaded, followed by the returned fields and the data source. No filler and nothing redundant.

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?

For a one-parameter read tool with no output schema and no annotations, the description compensates well by listing the returned fields and naming the data source. The remaining gap is error/not-found behavior and the hash format contract, which are minor for a simple lookup.

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 description coverage is 0% and the single nested 'hash' property is undocumented in the schema. The description's 'by hash' clarifies that the argument is a transaction hash (not a block hash or address), which adds real meaning, but it does not specify the expected hex format or length.

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 ('Base transaction lookup by hash') and enumerates exactly what it returns (sender, recipient, value, calldata, gas, block). This clearly separates it from siblings like base_receipt, base_block, and base_call without needing to open a 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?

Usage is implied by 'lookup by hash' - the agent can infer it needs a transaction hash - but there is no explicit when-to-use guidance, no mention of the alternative base_receipt for status/logs, and no stated prerequisites or failure conditions.

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