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

Annotations already declare the tool read-only, idempotent, and non-destructive. The description adds valuable behavioral context beyond annotations by disclosing the 0.0005 XNO charge via x402, which is critical for an agent deciding whether to invoke it. No contradiction exists between the description and annotations.

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 compact and front-loaded: the first sentence states the data payload, and the second adds the cost. Every sentence earns its place, with no filler or redundant elaboration.

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?

Given the low complexity of a single-parameter tool, the fully documented schema, the presence of an output schema, and annotations covering side effects, the description is complete. The unusual and important cost detail is disclosed, and nothing essential for invoking the tool correctly is missing.

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% for the single account parameter, including the address format and the fields it returns. The description largely repeats these same fields rather than adding new parameter semantics beyond the schema, so the high-coverage baseline of 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 clearly identifies the resource (Nano accounts) and enumerates the exact data returned: balance, representative, block count, frontier, weight, and pending transactions. It uses the noun phrase 'account intelligence' rather than an explicit verb, but the scope is unambiguous and clearly distinct from the web/URL-focused sibling tools.

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 usage context is implied by the resource description: use this when you need Nano account information. However, there is no explicit guidance about when to choose this tool over alternatives or when not to use it, though none of the listed siblings appear to overlap functionally.

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