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

With no annotations, the description carries the full burden and does well: it discloses the tool is read-only, queries balanceOf at the latest block (point-in-time, not historical), and operates on whole-token units. It omits error behavior for invalid wallet/token inputs, keeping it short of a 5.

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 short sentences, front-loaded with the core question, then mechanism, then use case. Every sentence adds distinct value with no redundancy.

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 3-param read tool with no output schema, the description covers purpose, mechanism, units, and a use case. The 'Does this...?' framing implies a yes/no result, making the return sufficiently clear, though it never explicitly states the response shape.

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 67% (wallet undocumented). The description adds meaning beyond the schema: token accepts 'any Base ERC-20' (not just AgentPad tokens), min is in 'whole tokens', and the use-case framing clarifies wallet as the payer/address being checked. This compensates well for the one undocumented parameter.

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 question the tool answers ('does this wallet hold at least min whole tokens...right now'), names the mechanism (read-only balanceOf at latest block), and is clearly distinguishable from all the build_*_tx and token-info siblings. An agent can tell exactly what this does without opening the 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?

Provides a concrete when-to-use scenario: sellers granting holder perks should verify the payer address of an x402 payment before granting. It doesn't name an alternative to route away from (e.g., check_vote_eligibility), but there is no direct sibling competitor for balance checks, so the guidance is strong though not exhaustive.

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