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

Annotations already declare read-only, idempotent, and non-destructive behavior. The description adds useful behavioral context: the AI-powered similarity logic, the grouping use case, the precision benefit of ZIP, and the cost ($0.01 USDC via x402). It doesn't cover rate limits or error behavior, but the added cost and key-generation details are meaningful 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?

Front-loaded with the core purpose, followed by usage guidance and cost. Every sentence adds value with no redundancy or 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?

No output schema exists, but the description explains that the return value is a similarity key and how to use it for grouping. Combined with the simple 3-parameter schema and the annotation set, the definition gives enough context to call the tool correctly. Only minor gaps (e.g., no mention of error modes) remain.

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 100%, so all parameters are already documented. The description mentions that ZIP is optional but recommended for precision, which matches the schema's own description. The 'algorithm' parameter is not mentioned in the description, but the schema covers that. Baseline 3 is 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?

States a specific verb and resource: 'generates an AI-powered similarity key for a street address.' The 'US' scope and 'similarity key' concept implicitly distinguish it from siblings like interzoid_global_address_match and interzoid_address_parse, but no sibling is explicitly named.

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?

Explains the primary use case clearly: 'Group on the key to find duplicate addresses, households, and locations.' It also notes that an optional ZIP improves precision. However, it does not state when to prefer this over alternatives (e.g., global_address_match or address_parse), so exclusions are missing.

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