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

Annotations already declare a non-destructive, idempotent, closed-world write, so the description's job is to add context — and it does: permission scope, actor binding (only the bound supplier), optimistic-concurrency semantics via expected_version, and an anti-fabrication rule for evidence. It does not disclose the resulting order state change (e.g., whether the order transitions to completed or what happens to funds), which is the main remaining behavioral gap.

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?

Roughly four short sentences, front-loaded with the action and scope, then constraints, then the version-conflict rule. Dense and mostly waste-free, though the telegraphic phrasing ('Read and review again on version conflict') is slightly compressed at the cost of clarity.

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 5-required-parameter mutation with no output schema, the description covers authorization, actor identity, versioning, and evidence integrity well. It leaves the caller without any statement of what a successful call returns or changes, and without guidance on the idempotency_key contract that the schema also fails to document.

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%, so the description must carry parameter meaning and only partly does. It adds real semantics for expected_version (must be exact; on conflict re-read and retry) and implicitly for evidence_reference (must be genuine completion evidence, never invented), but idempotency_key and order_id are never explained, and completed_at's format/units are left entirely to the integer schema.

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+resource: reporting actual completion evidence against an already paid/confirmed order. This clearly separates it from read siblings (evuun_get_business_order) and from decision siblings (evuun_decide_business_order), reinforced by the note that it does not substitute for buyer acceptance or settlement. No sibling is named explicitly, so it stops short of a 5.

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?

Gives concrete preconditions (orders:manage permission, exact expected_version, caller must be the bound supplier) and an explicit exclusion (this does not substitute for buyer acceptance or settlement). It also prescribes recovery behavior on version conflict. It never names the sibling tool to use for acceptance/settlement, which keeps it from a 5.

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