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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and non-destructive intent. The description adds valuable behavioral context beyond that: it is live from the NEAR RPC, requires only the 'account' input, and includes pricing details (x402 on Base, x-credit-token header, free tier). This goes beyond the annotation safety profile and helps the agent understand operational constraints.

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 description is slightly long (multiple clauses and pricing information) but every sentence contributes: the opening question sets purpose, the body enumerates checks, and the closing covers access and cost. It is front-loaded with the most critical information and does not contain filler. It could be tightened, but it is well-organized for its complexity.

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?

The tool has moderate complexity with an output schema, and the description explains the purpose, inputs, behavioral flags, and access/pricing. It does not describe the return format, but the output schema covers that. Combined with annotations, the description gives an agent everything needed to decide when and how to call it successfully.

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% for the single parameter, and the schema description already says 'NEAR account'. The tool description merely reiterates 'Required input: account' without adding format, validation, or examples. Since the schema carries the parameter meaning, the description adds no significant extra semantic value, so baseline 3 is appropriate.

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 opens with a precise, interrogative purpose ('What is this NEAR account, and who controls it?') and then lists concrete attributes it checks (existence, type, balance, contract/token status, keys). This is a specific verb-plus-resource definition that clearly distinguishes it from generic address tools without needing to name a sibling.

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?

The description provides a clear trigger condition ('Before an agent pays or trusts a NEAR account'), which tells the agent when to invoke it. It does not explicitly name alternative tools or give when-not-to-use conditions, but the context is strong enough to route appropriately given the large sibling set.

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