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

Beyond the annotations (readOnlyHint=false, idempotentHint=true, destructiveHint=false), the description adds crucial domain behavior: the tool never charges money, first-party orders produce a verified payment handoff, and external-seller funds remain blocked. This is meaningful transparency for a financial contract tool.

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?

Three short sentences, front-loaded with the core action, then two precise behavioral constraints. No filler, no repetition, easy to scan.

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 and annotations present, the description still supplies important payment-flow context. It omits usage guidance relative to siblings and auth/prerequisite details, but overall it is nearly complete for an agent to call the tool safely.

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 80%, so the schema already documents most parameters. The description adds no parameter-level details, which is adequate given the high schema coverage but not additive.

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 states a specific verb and resource: 'Create an immutable A2A order contract.' It is clear what the tool does, but it does not explicitly differentiate itself from siblings like nexus_trade_create_offer or nexus_trade_my_orders.

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 behavioral context about payment handling for first-party vs external-seller orders, but it never states when an agent should create an order rather than an offer, nor does it name alternative tools or prerequisites.

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