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

Beyond the annotations it discloses error semantics (404 for no contract, 422 for non-ERC-20, both uncharged), pricing ($0.01/call via x402 or card key, first 25 free, failed calls free) and the fact that each call is charged so repeats are not free, which explains the otherwise puzzling idempotentHint=false. This is exactly the extra context annotations cannot convey.

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 core purpose is front-loaded and the alternative and return fields follow in a logical order. The single dense paragraph is slightly overlong, and 'changes nothing' partly repeats the readOnlyHint annotation.

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 enumerates the returned fields (raw amount, decimals, symbol, human-readable amount) so an agent knows the response shape. Combined with error codes, pricing and safety, an agent has everything needed to call this correctly.

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 and the schema already documents both parameters. The description adds a 40-hex-character constraint, but the phrasing 'both inputs are 0x addresses' conflicts with the schema's allowance of a ticker (USDC/DAI) for the token field, so it adds ambiguity rather than clarity.

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 (get balance), resource (ERC-20 token of a wallet on Berachain) and the mechanism (balanceOf), and explicitly names the sibling to use instead for the native coin (bera_balance). An agent can distinguish it from bera_token_info and bera_balance without opening any 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 when-to-use ('check stablecoin or token holdings before a transfer or trade') and a named alternative with its condition ('for the native coin use bera_balance'). Nothing about tool selection is left to inference.

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