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

With no annotations, the description carries the burden, and it does well: it discloses that values are read at the latest block and may change due to reorgs, and it states the exact cost per call. It does not cover response shape or error cases, but the disclosed read-only nature and pricing are meaningful.

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?

Three sentences, each earning its place: core outputs, optional token usage, and behavioral/cost caveats. The most important information is front-loaded, and there is no redundancy or filler.

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 simple read tool with three documented parameters and no output schema, the description is complete. It enumerates the returned values, the optional token expansion, the chain context via schema, and the cost/reorg caveats. An agent has enough to call it 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. The description adds a small amount of value by explaining the token parameter's purpose in context, but it mostly restates what the schema already says. It does not harm or significantly extend parameter understanding.

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?

The description names exactly what the tool returns: native balance, next nonce, and whether the address holds contract code. This clearly separates it from siblings like token_info and tx_status by focusing on pre-send address state.

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?

It gives a clear use case: the three things needed before sending from or to an address. It also explains when to add the token parameter. It does not explicitly compare against sibling tools, but the context is sufficient for an agent to know when to invoke it.

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