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

Annotations already declare readOnlyHint and openWorldHint, but the description adds materially important behavior the annotations cannot convey: a per-call cost of $0.002 USDC via x402 across three payment rails, and that failed calls are not charged. It also discloses data provenance (ACRIS master file) and freshness ('recently recorded'). It does not state volume implications or pagination limits beyond what the schema covers.

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, front-loaded with the data source and returned fields, followed by scope caveats and then pricing. The pricing sentence is long but earns its place by warning of a cost model before invocation; no filler prose.

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 description needn't explain return structure, and it correctly focuses on source, scope caveats, and cost. Minor gaps remain: it doesn't clarify how recent 'recently recorded' is or whether results are capped at the schema's 50-document limit, which matters for an open-world paid query.

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% – limit, borough, and docType are each documented in the schema itself. The description's mention of document type examples (DEED, MTGE) and borough coverage merely echoes the schema rather than adding constraints or format nuances beyond it, so the baseline 3 applies.

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 names a specific resource (recently recorded NYC real-property documents from ACRIS/NYC Open Data) and enumerates the returned fields (document type, dates, borough, amount). It explicitly corrects the misleading tool name ('Not limited to commercial property') and distinguishes itself from a sales-price database, which helps differentiate it from siblings like realestate_nyc_property_sales. It stops short of an explicit retrieval verb or naming a sibling to use instead.

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 provides clear context for when this is the right source (NYC recorded property documents from ACRIS) and an explicit exclusion ('not a sales-price database', 'not limited to commercial property'), which steers agents away from misusing it as a price feed. It does not explicitly name alternative tools for non-NYC or pricing queries.

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