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

No annotations are provided, so the description carries the full burden. It does disclose a genuinely useful behavioral trait — the call is FREE with no payment required — which is meaningful in a payment-gated tool ecosystem. It does not disclose return behavior for unlabeled addresses, rate limits, or data freshness.

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?

A single sentence that front-loads the purpose, then parenthetically conveys coverage breadth and cost. Every clause carries information an agent can use; no waste 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 one-parameter read tool with no output schema and no annotations, the description covers purpose, corpus scope, and cost. It could note what is returned when no label exists (a gap given there is no output schema), but otherwise it is complete enough to invoke correctly.

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?

Only one parameter exists and schema description coverage is 100%, so the schema already documents the '0x + 40 hex' format fully. The description adds no format, validation, or normalization guidance beyond what the schema supplies, so the baseline 3 applies.

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 and resource ('Get a human-readable label for an EVM address') and adds useful scope detail about the label corpus (exchanges, bridges, protocols, scams). It does not explicitly distinguish itself from the sibling search_labels_by_category, which is the closest alternative, so it falls short of a 5.

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?

Usage is implied: an agent with an address wanting a label would pick this. However, the description never states when to use this versus search_labels_by_category or how it relates to get_address_risk_score, so no explicit when/when-not guidance is given.

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