council_tax_query

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

Annotations already declare readOnlyHint=true, openWorldHint=true, and idempotentHint=true, so the safety profile is covered. The description adds meaningful behavioral context: it specifies the data source (AddressBase Premium), the record type (Application Cross Reference), and the flag semantics (Council Tax and non-domestic rates). It also clarifies the activeOnly parameter's meaning via schema description, but the description itself doesn't add much beyond the schema. However, the description's mention of 'flags' and 'cross reference records' gives useful domain context beyond annotations.

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?

A single, information-dense sentence that front-loads the verb, resource, and purpose. No wasted words. It earns its place by adding domain context that the schema and annotations do not provide.

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 tool's moderate complexity (3 params, 1 required, output schema present), the description is sufficient for an agent to understand what the tool does and when to call it. The output schema exists, so return values need not be described. The only gap is explicit usage guidance versus alternatives, but the domain context and parameter semantics are clear enough for correct invocation.

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 67%: the 'uprns' and 'activeOnly' parameters have descriptions, but the 'tool' const parameter is self-explanatory. The description adds meaning by explaining that UPRNs are used to query AddressBase Premium cross-reference records and that the output identifies Council Tax/non-domestic rates flags. This complements the schema's parameter descriptions, which already explain the activeOnly default and UPRN format.

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 ('Query'), a specific resource ('AddressBase Premium Application Cross Reference records'), a key parameter ('by UPRN'), and the purpose ('identify Council Tax and non-domestic rates flags'). This clearly distinguishes it from siblings like council_tax_band_lookup and os_places_by_uprn.

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?

The description implies usage: use when you need Council Tax/non-domestic rates flags for UPRNs. It does not explicitly state when not to use it or name alternatives (e.g., council_tax_band_lookup for band lookup, os_places_by_uprn for general address data). The sibling list provides context but the description itself gives no routing guidance.

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