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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description adds value by enumerating what is returned (volumes, layer heights, tiers, MOV) in the absence of an output schema, which is the main behavioral fact an agent needs. It does not describe response size or format, keeping it below a 5.

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?

Two sentences, front-loaded with the payload contents and closed with the decision rule. Every clause maps to either what is returned or when to call it; nothing is redundant.

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 zero parameters, rich read-only annotations, and no output schema, the description carries the return-value burden and does so by listing the capability categories. Adequate for correct invocation, though it could note whether the result is static reference data or account-specific.

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?

The tool takes zero parameters, so there is nothing for the description to disambiguate; baseline 4 applies. The schema's empty properties object is consistent with the description's framing as a parameterless catalog query.

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 enumerates precisely what the tool returns: technologies, build volumes, layer heights, file formats, production tiers, minimum order value, and on-request options. The resource ('what 3Descu can manufacture') is specific enough that an agent can distinguish it from analyze_model, estimate_price, and list_materials, though no sibling is named explicitly.

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?

'Call this first if you do not know whether a part is feasible' gives a clear trigger condition and positions the tool as a discovery step ahead of the analysis/pricing siblings. It stops short of stating when not to call it (e.g., if feasibility is already known), but the guidance is actionable.

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