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

Annotations already declare readOnlyHint and openWorldHint, so safety is covered. The description adds a genuinely useful behavioral fact not in annotations: the credit cost (1 per record, minimum 2) and the advice to keep page_size down. It stops short of describing pagination limits or return shape, hence not a 5.

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 sentences, all front-loaded and purposeful: purpose first, cost second, routing/filter guidance third. No filler, though the region_type enumeration slightly duplicates the schema.

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 an output schema present, return values need no explanation, and the description covers purpose, cost, filtering, and sibling routing. Complete enough for correct invocation, with only minor gaps on pagination/limit semantics.

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%, so the schema already documents all 24 parameters including enums like region_type and property_type. The description only restates region_type values and points to filter categories, adding marginal meaning beyond the schema. Baseline 3 is appropriate.

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 (monthly U.S. housing-market statistic records from Redfin joined with Census income for affordability). It also distinguishes itself from siblings by naming facets and item tools, so an agent can tell it apart without opening schemas.

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?

Explicitly routes the agent: use datasets_housing_markets_facets for filter values and datasets_housing_markets_item for a single region. It also explains the region_type and filter categories to use, giving clear when-to-use guidance and named alternatives.

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