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

Annotations already cover the safe-read profile (readOnlyHint, destructiveHint=false, openWorldHint), but the description adds material behavioral context beyond them: the asynchronous 'pricing' state and the need to poll, plus the explicit no-side-effect/no-charge guarantee. It does not say how long pricing takes or what happens on failure.

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, purpose front-loaded, with the async caveat and the no-cost guarantee following compactly. 'Cheap.' is terse but carries pricing-relevant signal; nothing is padded.

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?

An output schema exists, so return values need little prose, and the description still contributes the state machine (ready vs pricing) that an agent must handle. Combined with 100% schema coverage on a nested-input tool, the definition is sufficiently complete.

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%, so the schema already documents slug, source, and the nested method object (process/material/quantity/reason) in detail. The description adds no parameter-level meaning beyond that, so the baseline 3 applies.

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: start or read the real price for making a part, with the two outcome states named. It is distinguishable from order_part (which presumably places an order) only indirectly through 'Creates nothing and charges nothing', so sibling differentiation is implied rather than stated.

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?

Explains the polling pattern ('call again in a few seconds') when status is 'pricing', which is genuine runtime guidance. However, it never says when to reach for this versus order_part, dfm_review, or fab_pack, nor what input is required to get a price.

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