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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds a genuine behavioral fact not present in structured data: the call is free (no cost/rate impact), which matters for an agent deciding whether to probe repeatedly.

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?

Two short fragments with zero padding; scope is front-loaded and the cost note follows. Every word carries information.

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 two-param read tool this is mostly adequate, but it omits what the return looks like (raw base units vs. decimal-adjusted balance, token metadata) and there is no output schema to fill that gap.

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% and both params are documented as keeta_-prefixed addresses, so the schema does the heavy lifting. The description only restates the cardinality (one token, one address) without adding format or validation detail beyond the schema.

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 verb+resource (fetch a token balance) and constrains scope to a single token on a single Keeta address. It does not explicitly name get_portfolio as the multi-token alternative, so differentiation from siblings is left to inference.

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 phrase 'One token balance on one Keeta address' implies this is the single-token lookup as opposed to get_portfolio/get_account, and 'Free' hints it is cheap to call, but the description never states when to prefer it over those siblings or any prerequisite conditions.

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