molding_screen

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

No annotations are provided, so the description carries the full disclosure burden and does it well: it states fidelity='exact' for cooling-only vs fidelity='correlation' with band_pct=30 (±30%) once flow_length_mm is added, lists the validation/return fields (valid_range_ok, warnings, flow_ratio_limit), and names the escalation target. Minor gap: no permissions/rate/precondition notes, but for a stateless calculator the accuracy/limitation disclosure is the material 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?

Purpose and the key design formula (t ∝ s²) are front-loaded, and nearly every clause conveys operative information such as fidelity switching and escalation. It is dense and leans on an inline equation and a long return-field list, which slightly hurts scannability but is not wasteful.

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 and no annotations, the description compensates by listing the returned fields and the fidelity/band semantics, which is exactly what an agent needs to interpret results. Combined with the escalation rule and the material/parameter rules, it is complete enough to invoke and interpret correctly, missing only explicit range/limit values.

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 8 params, so the description must compensate and largely does: it explains that material selects per-polymer defaults (ABS|PP|PC|PA66|POM|HDPE|PS) and is individually overridable, that all temps plus alpha_mm2_s make material unnecessary, and that flow_length_mm triggers the fill check. It leaves some params (t_melt/t_mold/t_eject relationships, flow_ratio_limit) implicit, so not full coverage.

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 names a specific verb+resource ('Injection-molding screen, NO solver') and enumerates exactly what it computes: one-term cooling time plus a spiral-flow fill check. It tells the agent how it differs from the sibling it would otherwise escalate to ('molding_fill_submit' for the VOF fill solve), so the tool is distinguishable without opening a schema.

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?

It gives explicit when-to-use branching: a cooling-only call is sufficient and needs no solver (escalate_to=None), whereas supplying flow_length_mm makes the headline a correlation and routes to molding_fill_submit. That is clear context and an alternative, though it never contrasts with near-neighbor siblings like moldability_screen/moldability_check.

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