Read live quantities

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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds real behavioral context — the values are live during a run and freeze to last-known values afterward — but says nothing about failure modes (unknown quantity names) or session prerequisites.

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?

A single front-loaded sentence that states the resource and the temporal behavior with no wasted words. Nothing is padded or restated from the title.

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 not be explained, and annotations cover the read-only/open-world profile. The description supplies the key temporal semantics; the only minor gap is whether an active session or run is required to obtain 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 100%; the single 'quantities' parameter is documented with a format example ('Time', 'Car.v'). The description adds no extra meaning beyond the schema, 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?

Names a specific resource ('CarMaker quantities') and its temporal scope ('current values during a run, or the last values after it'), which clearly separates it from batch result readers. It does not name or contrast any sibling such as cm_read or cm_output_quantities, so an agent must infer differentiation from the temporal qualifier alone.

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?

The parenthetical 'during a run (or the last values after it)' implies when the tool is applicable, but there is no explicit when-to-use/when-not-to-use statement and no named alternative for post-run data (e.g., cm_results_read). Usage is inferable rather than stated.

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