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

Annotations already declare readOnly/idempotent/non-destructive/openWorld=false. The description adds meaningful context beyond that: it requires the cenpy package, accepts an optional free Census API key, falls back to rate-limited unauthenticated access, and cites the ACS 5-Year source. It does not address the numerous extraneous filter params, but the core behavioral profile is well disclosed.

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 purpose, then structured with 'Key metrics returned' and 'Use this tool when' sections. Slightly verbose in the metrics/dependency prose, but every section is scannable and largely 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?

An output schema exists, so return-value explanation is technically redundant but harmless. The description covers the data source, dependencies, and use cases; the only gap is that the many administrative/overlay params (wholesaler_ids, source_resource_id) aren't addressed, though the schema handles them.

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 itself documents each parameter thoroughly (state, zip_code, api key, caching, etc.), so the description doesn't need to re-explain them. The description reinforces the state-vs-ZIP targeting and lists return metrics, but adds little parameter syntax beyond what the schema provides — baseline 3 for schema-covered params.

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 and resource: retrieve US Census ACS income/wealth proxy data for a ZIP code or state, and lists the exact metrics returned. An agent can immediately tell this apart from data/stock siblings like GetFinancials or GetPriceHistory.

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 'Use this tool when' bullets give clear operational context (scoring territory wealth, comparing income distributions, pre-overlay proxy). No explicit when-not or alternative routing is given, which keeps it below a 5, but the usage guidance is concrete.

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