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

Annotations already declare readOnly, idempotent, non-destructive, and openWorld. The description adds real behavioral value on top: a $2.50 USD cost, the 'without selecting a winner' constraint, and the shape of what comes back (completeness metadata, source gaps, provenance manifests). It does not mention auth requirements or rate limits, but the cost and output scope are meaningful additions.

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?

Cost and purpose are front-loaded, which is good, but the single sentence then trails off into a long enumerated list of output artifacts (bounded evidence highlights, completeness metadata, source gaps, provenance manifests, drilldowns) that partly duplicates what the output schema already covers.

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, the heavy output enumeration is largely redundant, while the genuinely missing pieces — how to choose this tool over the single-site siblings and what the input sites must contain — go unaddressed. Adequate but with clear gaps for a paid comparison tool.

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 0%, so the description must carry the load. It conveys the cardinality (two or three sites) and implies SF-only addresses, but adds no format or meaning for the nested address/city/unit/label/state fields beyond their self-evident names.

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 (compare) and resource (two or three candidate San Francisco sites) across named evidence dimensions, and adds the crucial scope qualifier 'without selecting a winner'. It is clearly distinct from single-property siblings like check_property, though it never names a sibling or addresses overlap with development_due_diligence or property_intelligence_pack.

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?

No when-to-use conditions, prerequisites, or alternatives are given. The agent is not told when this multi-site comparison is preferable to running the single-site check tools, nor what happens with fewer than two or more than three sites beyond the schema's min/max.

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