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

Annotations already mark it read-only/idempotent/non-destructive, and the description adds real behavior beyond that: it breaks the brief into 'one to three parallel structured searches', merges and ranks results, returns 'up to 9 listings with match scores', and discloses interpretation limitations ('what couldn't be resolved'). This is substantial, non-obvious behavior.

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 with no filler: the purpose, the ideal input profile, and the processing/output contract. The example is illustrative but compact, and all sentences add information.

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?

Given the output schema and annotations, the description covers input, interpretation mechanics, and return shape. It is slightly incomplete because it never conditions this tool against search_properties for structured queries, and the language parameter is left unexplained.

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 description enriches the 'brief' parameter by characterizing acceptable input as vague, conditional, or lifestyle-heavy, but it does not discuss the 'language' parameter at all. Schema coverage is exactly 50%: brief has a description, language only has an enum/default, so the description only partially compensates for that gap.

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?

The description opens with a specific verb and resource: 'Match Spanish properties from a free-form description of what the user wants.' The example and mention of 'PropertyList's full MLS' ground what it acts on. It is clearly distinguishable from the sibling search_properties because it targets vague, lifestyle-heavy briefs rather than structured queries.

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?

It states when to use it: 'Best for vague, conditional, or lifestyle-heavy briefs' and gives a concrete example. It does not explicitly name an alternative for structured queries or state when not to use it, but the positive guidance is clear enough.

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