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

Annotations declare readOnlyHint=false, which conflicts with a read-only fetch operation — but the description's billing context ('billable property-record path and bills per API terms') may justify the false readOnly flag. The description adds important behavioral context: it never returns nested arrays or person contact data, rejects Contacts-group field ids, and is a billable path. It does not explain the readOnlyHint=false discrepancy, leaving potential ambiguity.

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 core purpose, then usage conditions, exclusions, and parameter details. Every sentence adds value, though the billing note and state coverage could be more tightly integrated. Slightly verbose but well-structured.

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 2 parameters, no output schema, and sparse annotations, the description covers purpose, usage, exclusions, billing, and parameter behavior thoroughly. It adequately compensates for the lack of output schema by describing return character (scalar fields, no nested arrays, no contacts). Missing only details like error handling or rate limits, which are minor.

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 compensate. It explains the 'fields' argument semantics well: defaults to Standard fieldset, accepts comma-separated field ids from get_fields, and Contacts-group ids are rejected. The 'radarId' parameter is described indirectly via context (issued for properties in any state), but its format is not specified. Good compensation overall.

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 specific verb+resource ('Fetch authoritative scalar property fields from PropertyRadar by RadarID') and clearly distinguishes itself from siblings like get_property_summary, get_property_persons, and resolve_address by specifying what it returns (scalar fields, not nested data) and what it doesn't (contacts).

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?

Explicitly states when to use it ('after resolve_address or get_property_summary when the user needs exact fields beyond the summary bands') and when not to use it ('Do not use this tool to identify an owner; use get_property_persons'). Names alternative tools with conditions, covering routing to get_fields and get_property_persons.

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