Get demographics by ZIP

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

Annotations already declare readOnlyHint=true and openWorldHint=true, and the description adds that the data are ACS 5-year estimates and that age-bracket breakdowns are on the roadmap. This provides useful context beyond the annotations without contradicting them.

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 description is two sentences (or three lines) long, front-loaded with the core purpose, and includes only essential details like the parameter format and the roadmap limitation. Every word earns its place.

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 read-only tool with one parameter and an output schema, the description covers the purpose, the parameter format, the data source, and what is not yet included. It is sufficiently complete without needing to explain return values in detail.

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 schema provides no description for zip_code (0% coverage), but the description includes '`zip_code`: a 5-digit US ZIP,' which supplies the format and meaning. This compensates for the schema gap.

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 that the tool returns population and median age for a ZIP, using the verb 'Returns' in the second sentence. It distinguishes itself from sibling tools like get_income or get_housing by naming the specific metrics it provides.

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: use when you need population and median age for a ZIP. There is no explicit mention of when not to use it or which alternative to pick for other demographics, though the roadmap note hints that age-bracket breakdowns are not yet available.

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