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

With no annotations provided, the description carries the full behavioral burden and does most of it: it discloses the cost model (1 validation credit, enrichment free), the refund rule for failed lookups, the match-quality gating that determines whether enrichment appears, and the parse semantics of the returned verdict. It does not mention auth requirements or rate limits, which keeps it from a 5.

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 lead line is front-loaded and the USA/Canada breakdown is scannable, with behavioral caveats and cost placed after the capability statement. It is dense but efficient; the source attribution line is the one element that doesn't strictly help an agent decide or invoke.

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 tool with no output schema and no annotations, the description covers the two things an agent most needs: what fields come back and when they will come back empty. The remaining gap is input assembly — which address fields to populate in what combination — which is not addressed.

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 0%, so the description must compensate, and it does so only partly. It adds a genuinely important constraint absent from the schema — `country` must be "usa" or "can" — but the other six parameters (notably the ambiguity between `address_line` and the `house_number`/`street` pair) are left entirely unexplained.

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?

Names a specific verb-like operation (address → census/geographic enrichment) and enumerates the exact codes returned for both the USA and Canada, so an agent can distinguish it immediately from validate_address and geocode_address. The two-country scope and field list leave no ambiguity about what the tool produces.

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?

States the key usage condition clearly: enrichment is only attached when the address resolves to house-number- or street-accurate matches, and centroid-only matches return nothing. It also pins the accepted `country` values. It stops short of explicitly routing the agent to validate_address or geocode_address when only validation or coordinates are needed, so no exclusions are stated.

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