Validate Address

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

With no annotations, the description carries the full burden. It discloses that the tool validates addresses against authoritative data and returns standardized addresses, rooftop coordinates, confidence levels, and UK-specific identifiers. It does not mention error handling or edge cases, but overall behavior is well explained.

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?

The description is extremely concise—two sentences that front-load the core purpose and then enumerate key return values. Every word adds value, with no repetition of schema information or unnecessary details.

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 7 parameters and no output schema, the description covers the tool's scope (240+ countries), input alternatives, and expected outputs. It could be more complete by describing error conditions or confidence score interpretation, but it is sufficient for most use cases.

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%, so each parameter already has a description. However, the description adds important context: it clarifies that 'input' can substitute fielded parameters and that 'state' is required for certain countries (USA, CAN, etc.), which is not evident from the schema alone.

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 clearly states the verb 'validate' and resource 'postal address', and distinguishes from sibling tools (geocode, postcode_lookup, reverse_geocode) by emphasizing validation against authoritative reference data and returning confidence scores and UK-specific IDs.

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 the tool is for validation but does not explicitly guide when to use it over siblings like geocode or reverse_geocode. It lacks explicit 'when to use' or 'when not to use' guidance, though the context of returning confidence scores hints at its validation purpose.

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