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

With no annotations, the description carries the full burden. It usefully discloses the Canadian fallback behavior (returns a Geolocator URL instead of proxying), but says nothing about the U.S. return format, error behavior, or the API-key/auth situation that the schema only partially covers.

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 tight sentences with zero waste; the primary U.S. behavior is front-loaded before the Canadian edge case.

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?

No output schema and no annotations, and the description doesn't describe the U.S. return value or which inputs are actually required to succeed. It covers the core intent and the Canada branch but leaves real gaps for an agent trying to call it 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?

Schema description coverage is only 17% across 6 parameters, so the description must compensate and largely doesn't. It explains nothing about which of city/state/street/postal_code are needed, what 'language' (en/fr) affects, or how api_key interacts with env config.

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 (geocode) and resource (U.S. street address) plus the backing data source (TIGER/Line). The geographic scoping immediately distinguishes its behavior from a generic geocoder.

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?

Clearly tells the agent to use this for U.S. addresses and to expect a URL rather than a proxied query for Canadian ones. It gives a clear context for use, though it doesn't address what to do when address parts are missing (0 required params).

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