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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the description earns credit for adding non-obvious context: the covered period (1975-2026), the three series types, and the 'aggregate federal statistic — zero PII' reassurance. It does not discuss pagination behavior or result ordering, which is a minor gap.

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?

Three compact sentences, front-loaded with the verb/resource and followed by the return value and the data caveats. The parenthetical series list is dense but informative; a small amount of trimming is possible without loss.

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?

With no output schema, the description correctly fills the gap by naming the returned identifier (place_id) and what it unlocks. Combined with full parameter documentation and annotations covering the safety profile, 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 coverage is 100%, so the baseline is 3, but the description adds meaning the schema lacks: the accepted geography granularities (metro, state, census division) beyond the schema's bare examples 'Austin'/'California'. It says nothing extra about the limit parameter, which is already fully documented in 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?

States a specific verb (Search) and resource (FHFA House Price Index) and narrows the geography granularity to metro/state/census division, which separates it from lookalike siblings such as income_by_zip_search and ag_census_county_search. It also states the key output (place_id), so an agent knows what it gets back.

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 clause 'Returns the place_id to pull a full house-price appreciation history' clearly positions this as the lookup step preceding a detail retrieval, which is genuine when-to-use guidance. It stops short of naming an alternative tool or stating exclusions (e.g. when to use a different geographic index instead).

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