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

The description goes well beyond annotations by disclosing that the operation is paid, settles USDC via x402 when EVM_PRIVATE_KEY is set, and otherwise returns a 402 probe. This is key behavioral context that an agent cannot infer from the schema or annotation flags.

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 deliver the core purpose, ordering guidance, payment mechanism, and fallback behavior with no fluff. The most important operational facts are front-loaded.

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 output schema exists and the input schema has full parameter documentation, the description adds exactly the missing operational context: paid status, sample-first order, settlement via x402, and 402 behavior. This is complete for an agent to decide and invoke the tool.

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 the input schema already documents all five parameters including examples. The description itself does not explain individual parameters, but the schema carries that burden, so the baseline score of 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?

The description clearly states a specific verb and resource: 'Run a paid US city property compliance check.' It also distinguishes itself from city.sample by explicitly telling the agent to prefer city.sample first, so the tool's role is unambiguous.

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 gives direct guidance to use city.sample before this paid check, which is a clear alternative-selection rule. It does not enumerate all when-not-to-use cases, but the preference ordering is sufficient for most agent decisions.

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