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

The annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds a genuinely non-obvious behavioral trait — containment is computed against the actual parcel boundary rather than the nearest centroid — which tells the agent edge-case and accuracy behavior it could not infer from structured fields. It still omits the no-match / overlapping-parcel outcome.

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?

Two short sentences, front-loaded with the core question and immediately followed by the semantic clarification. No filler, no restatement of the title.

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 simple two-parameter read-only lookup with full schema coverage, the description supplies purpose plus the key accuracy caveat. Remaining gaps — behavior on no match and result multiplicity — are minor given the tool's simplicity, though slightly more would make it airtight in the absence of an output schema.

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% with two required numeric parameters, so the schema already documents lat and lon. The description adds no coordinate-system, precision, or format detail beyond the schema, leaving the baseline 3 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?

The description states a precise spatial question — 'Which parcel contains a latitude/longitude' — which is a specific resource (parcel) plus an implicit containment verb, clearly distinct from siblings like get_property and search_properties. It stops short of naming an alternative tool explicitly, so the differentiation is inferred rather than stated.

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?

Usage is implied: call this when you have coordinates and need the containing parcel. There is no explicit 'use X instead when...' routing against get_property, search_properties, or owner_portfolio, and no note on prerequisites or what to do when a point falls in an unincorporated gap.

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