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

Annotations declare read-only, idempotent, and open-world hints. The description adds that it returns matching locations with coordinates, consistent with annotations. It also mentions integration with RapidAPI/Realtor.com, offering useful context beyond 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?

Two sentences: the first conveys the core function and output, the second provides usage context. No unnecessary words, perfectly front-loaded.

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?

Given only one parameter and an existing output schema, the description sufficiently covers the tool's purpose and usage. It explains the autocomplete behavior and typical use case, leaving no critical gaps.

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?

The single parameter 'query' has 100% schema coverage with a description. The description adds example values ('Austin TX', '90210') that clarify the expected input format, adding value 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?

The description clearly states the verb 'autocomplete' and the resource 'location search for US real estate', specifying it returns cities, ZIP codes, and addresses with coordinates. This effectively distinguishes it from numerous sibling location tools that geocode or look up addresses.

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 description explicitly says 'Use to find valid city/state codes for property searches (RapidAPI / Realtor.com data)', providing context for when to use this tool. While it doesn't list exclusions, the purpose is well-defined and differentiates from siblings.

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