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

The annotations already declare this is a non-read-only, non-destructive write operation. The description adds meaningful behavior beyond that: new versions are immutable and the last valid version is never overwritten. However, it does not explain idempotency behavior despite the required idempotencyKey, nor does it clarify expectedVersion concurrency semantics or validation failure behavior.

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 with no wasted wording. The key behavioral constraint is stated immediately and compactly.

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?

This is a complex 11-parameter mutation with an output schema and non-trivial versioning semantics. The description covers immutability but omits critical context around idempotency, concurrency via expectedVersion, item structure, and validation behavior. It is too thin for the tool's complexity even though annotations and the output schema reduce some burden.

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% across 11 parameters, including required idempotencyKey, jobId, and items. The description names no parameters and provides no meaning for fields like expectedVersion, marginLabour, contingencyPercent, or vatEnabled. It does not compensate at all for the undocumented 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?

The description states a specific verb and resource: 'Creates a new immutable estimate version.' It also clarifies the versioning behavior, which distinguishes it from a plain update operation. It does not explicitly differentiate from sibling draft-creation tools such as create_quote_draft or create_variation_draft, but the resource is clear.

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?

There is no explicit guidance on when to use this tool versus alternatives, nor any stated prerequisites. The implied use case is saving an estimate draft, but an agent must infer when a new version should be created instead of using get_estimate or another draft-creation sibling.

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