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

Annotations already declare readOnly, idempotent, non-destructive, closed-world, so the safety profile is covered. The description adds genuine value by naming the data sources (Census ACS, FHFA House Price Index) and noting periods and sources are included, which tells the agent about data provenance and vintage. It stops short of covering update cadence, coverage limits, or failure modes, so a 3 is appropriate.

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?

A single dense sentence with no filler, and the country scope is front-loaded so the agent filters it against siblings immediately. The parenthetical source attributions interrupt the flow slightly but each earns its place by indicating data provenance.

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 one-parameter lookup with no output schema, the description adequately signals the return payload (median value, one-year change, periods, sources) so the agent knows what it gets back. The only real gap is the absence of routing guidance against closely related US tools.

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 100% and the single 'state' parameter is already documented with accepted formats, so the baseline is 3. The description adds one implicit detail — that city is not a parameter but is derived as the state's main city — but nothing about the state value syntax 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?

States a specific verb+resource: median home value for a US state and its main city, plus the one-year price change. The 'UNITED STATES' prefix clearly disambiguates it from house_prices_au/uk/in and the other country-specific siblings. It does not, however, explicitly contrast itself with near-neighbors like state_overview_us or compare_states_us.

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?

There is no when-to-use guidance, no exclusions, and no named alternative. An agent cannot tell from the description whether to call this or state_overview_us / compare_states_us for a given user question.

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