lookup_property

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

With no annotations, the description carries the full burden. It clearly indicates a read-only lookup operation returning multiple data categories. No mention of side effects or authorization, but for a simple property lookup, this is adequate and not misleading.

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 concise sentences with front-loaded purpose. Every sentence adds value: first states action, second lists returns and usage guidance. No fluff.

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 doesn't need to detail return structure. It lists all major return categories. The tool has one required param, and the description is complete. Siblings are many, but the description clearly positions this as the primary entry point.

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?

Single parameter uprn with schema description 'Unique Property Reference Number (12-digit string)'. Description adds context: it's a single UPRN, and the tool returns the canonical record. This enhances the parameter's meaning beyond the schema.

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?

Description explicitly states action ('Look up the canonical Homedata property record for a single UPRN') and lists return fields (address, geometry, council, etc.). Positions itself as the entry point, distinguishing it from sibling tools like batch_property_lookup and search_address.

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?

Includes explicit guidance: 'Use this as the entry point when you need ground-truth metadata for a property.' This tells the agent when to use it. While it doesn't list exclusions or alternatives, the context is clear enough to differentiate from siblings.

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