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

With readOnlyHint and idempotentHint already supplied, the description adds the important behavioral detail that the tool returns protocol-level history rather than trusted display identity. It does not enumerate the contents of the history, but the safety profile is already covered by 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?

The description is a single front-loaded sentence: it begins with the operation, states the scope, and ends with the purpose. There is no repetition of schema fields or annotations and no filler.

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?

For a one-parameter, read-only, idempotent endpoint without an output schema, the description gives enough information to select and invoke it: what is returned, from whom, and why. It could be more specific about the shape of 'protocol history' or how to source the address, but those are minor for this simple interface.

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 0%, but the only required parameter is a clearly named address with a strict regex. The description adds meaning by tying that address to the order-matched buyer, so an agent can infer what value to pass; still, it never explicitly states 'address is the buyer's address.'

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 names a specific action ('Return protocol history') and a specific resource ('the buyer that matched an order'), and it frames the endpoint as a verification mechanism rather than a display-name lookup. This is enough to distinguish it from sibling tools such as peer_cash_order or peer_cash_fill_stats.

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?

It clearly states the intended context: use it after an order match when an automation needs to assess delivery context and cannot rely on display identity. It does not name sibling alternatives or say when not to use it, so it stops short of a 5.

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