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

Annotations already establish readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds one genuinely new fact — authentication is required ('Needs your key') — but says nothing about result size, pagination, ordering, or what the list entries contain.

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, zero filler, with the purpose front-loaded and the disambiguation and auth note following in order of importance.

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-optional-param read-only list tool with no output schema, nearly everything needed is present: identity scoping, role semantics, alternative tool, auth requirement. The only missing piece is what the default (no role) returns.

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% and the role enum is fully documented in the schema, so the description's 'as buyer or seller (role)' adds no meaning beyond it. Baseline 3 applies; the behavior when role is omitted (both roles?) is left implicit.

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?

Specific verb + resource ('List your orders') with scope narrowed to the caller's own orders and a buyer/seller split. It also names the sibling get_order and the distinction (single order with delivery), so an agent can route without opening schemas.

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?

Explicitly routes single-order lookups to get_order, which is the key alternative among siblings. It stops short of stating when-not to use it (e.g., versus my_disputes or sales_statement for related data), so it is clear but not fully exhaustive.

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