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

Adds real context beyond the annotations: pricing ($0.01/call via x402 USDC or card key, first 25 free, failed calls free), the fact that repeat calls are not free (matching idempotentHint=false), and that it is read-only. The only flaw is 'takes no input,' which is contradicted by the optional `only` parameter in the schema.

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 the return contents, then alternatives, then pricing and safety in one compact block. Slightly dense with billing boilerplate, but every sentence carries information an agent may need before paying for a call.

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, yet the description names the returned fields and units (gwei, base fee, priority fee, transfer cost), so the agent knows what it gets. Pricing, safety, and the sibling alternative are all covered, leaving nothing needed for correct invocation.

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 100% and the single optional `only` filter is fully documented there, so the baseline is 3. The description adds no meaning to it and in fact says 'takes no input,' which subtly misleads about the parameter's existence.

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 for a specific chain and enumerates exactly what is returned (gas price, base fee, priority fee in gwei, 21,000-gas transfer cost). It also names the sibling it is not (bera_receipt for past transactions) and could be told apart from bera_gas_history without opening 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?

Gives explicit timing guidance ('use before sending a transaction or to decide whether to wait') and an explicit alternative with its condition ('for the fee a past transaction actually paid use bera_receipt'). No inference required.

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