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

With readOnlyHint and openWorldHint annotations already declaring the read-only and open-world nature, the description adds value by disclosing the return units (wei hex/decimal and ether). It does not mention edge cases or errors, but the annotations cover the safety profile and the added return format context is useful.

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 a single, front-loaded sentence that clearly states the action, target, and return format. Every word contributes meaning, with no filler or 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 read-only tool with one parameter and no output schema, the description covers the essential purpose and return format. It does not discuss error handling or invalid addresses, but given the low complexity and the presence of annotations, this is sufficient and well-rounded.

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?

The input schema has a single 'address' parameter with only a regex pattern and no description, and schema description coverage is 0%. The description only says 'for an address' without adding any semantic detail (e.g., format expectations, network specifics, or examples), so it fails to compensate for the schema's lack of detail.

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 states the tool gets the native token balance for an address on Mezo, with a specific verb and resource. It also specifies the return format in wei (hex and decimal) and ether, distinguishing it from sibling tools like mezo_get_token_balance and btc_get_balance.

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 clear context: it is for native token balances on Mezo, implying usage for MEZO native assets rather than token contracts or other chains. However, it does not explicitly name alternatives or exclusions, so it falls short of full guidance.

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