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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so 'without moving anything' mostly restates what structured data provides. The description does not explain what the reported correction consists of (units, per-shape vs aggregate, coordinates) — notable given there is no output schema.

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?

One sentence with no filler, and the non-mutation constraint is front-loaded. But the brevity comes at the cost of under-specification rather than efficiency — it is short because it says almost nothing.

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 no output schema, three undocumented parameters, and an enumeration the agent must guess at, the description leaves critical gaps: what the returned correction is, in what units, and whether shape_ids/container_id scope the result. It is not sufficient to call the tool correctly without trial and error.

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 three parameters: axis (enum both/horizontal/vertical), shape_ids, and container_id are entirely undefined in both schema and description. The description does not compensate at all — it never mentions scope, coordinate system, or what the axis restriction does to the measurement.

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 verb ('Report') and resource ('optical-centre correction') are specific, and 'without moving anything' implicitly contrasts it with the mutating sibling optical_center. It never names that sibling, so an agent must infer that optical_center is the tool that applies the correction.

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 when-to-use statement, no prerequisites, and no named alternative, despite optical_center being the obvious counterpart. The non-mutating phrasing only faintly implies a 'preview before applying' workflow; nothing routes the agent between the two tools.

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