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

Annotations already declare readOnlyHint=true, openWorldHint=false, and destructiveHint=false, but the description adds materially more: it is never billed, it echoes the Suggestions API payload shape verbatim, empty prefix matches return results: [], and every success carries related_tools[]. Those are behavioral facts an agent cannot derive from the annotations.

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?

Front-loaded with the core purpose and requirement, then usage rules, then return shape — a sensible ordering with no filler sentences. It is dense and runs long for what is a four-parameter lookup, with a couple of clauses that could be tightened, but every sentence still carries actionable content.

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?

There is no output schema, yet the description specifies the return contract (results[] with label and criteria fragments as the Suggestions API returns them, plus related_tools[]) and the empty-match case. Combined with the required/optional parameter split and the sibling routing, nothing an agent needs to call this correctly is missing.

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 carries the full burden and does so: suggestion_field is enumerated (City, County, or Subdivision), query is described as prefix/typeahead, criteria is an API-format scope array with an example (State before City or County), and limit is identified as optional. This adds meaning well beyond the bare schema types.

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 (non-billable value lookup / suggestion resolution) and immediately scopes it as a pre-step before search_properties. It distinguishes itself from siblings by naming search_properties and resolve_address as the alternatives, so an agent can route without opening another schema.

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?

Explicitly states when the call is required (every County name), when it is optional (incomplete/ambiguous City or Subdivision), and when NOT to call it (a complete City paired with a two-letter State, which goes straight to search_properties). It also excludes address fields and points to resolve_address, covering alternatives rather than leaving them to inference.

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