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

Annotations already declare readOnly/openWorld/non-destructive, so the safety profile is covered. The description adds genuinely non-obvious behavior: results are paginated, and a street-address or building-name input collapses to a single property card where the `type` parameter no longer applies. Auth and rate-limit behavior are not mentioned, which keeps it below 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?

Front-loaded with the operation and mode, then details. The return-field enumeration is long, but it substitutes for a missing output schema, so it earns its space. Slight density, but no redundant sentences.

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 59-parameter, no-output-schema tool, the description covers purpose, input modes, result-shape variation, returned fields, and the sibling relationship. Nothing essential to a correct call is left unstated.

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% and the schema already spells out every filter and enum, so baseline is 3. The description earns above baseline by documenting a semantic rule the schema never states: that required `type` is ignored for address/building searches, plus the set of location formats `keyword` truly accepts.

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 precise verb+resource (search for-sale/for-rent/sold Redfin listings) and its scope (pagination, location input forms). It explicitly distinguishes itself from the sibling by noting that deep-dive details come from the Redfin Property endpoint, so an agent can route without opening either schema.

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?

Gives concrete use cases (market research, agent lead gen, price/DOM trend analysis) and names the downstream alternative for detail lookups. It also flags the special case where an address/building input returns a single card rather than a list. It stops short of an explicit 'use X instead when Y' exclusion statement.

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