time_step_from_cfl

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It provides the formula, indicating a deterministic computation, but omits essential details such as units, error handling for non-positive velocities or cell sizes, and whether it returns a single scalar. The lack of caveats or assumptions leaves the agent uncertain about edge cases and output format.

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?

The description is a single, compact sentence that immediately states the purpose and the governing equation. It contains no filler or repetition, and the essential formula is front-loaded, making it efficient for quick comprehension.

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?

For a straightforward calculation with three parameters and no output schema, the description is nearly complete: it gives the formula and implies the return value (the time step). However, it lacks explicit mention of the expected output type or units, and does not provide context on when this calculation is appropriate (e.g., for stability in transient CFD). Given the sibling tools are all CFD-related, some context is implicit, but the boundary could be clearer.

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 description maps each schema parameter to a variable in the formula: velocity→U, cell_size→dx, target_courant→Co, thereby clarifying their roles beyond the bare schema names. This adds meaningful semantic value, though it does not specify units, value ranges, or constraints, which would be further helpful.

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 clearly states the tool computes a time step from a target Courant number and provides the formula, making the purpose explicit. It is distinct from sibling tools like y_plus_from_height or first_cell_height, which compute different quantities. However, it does not explicitly name the parameters or differentiate itself with a targeted sentence, only implying them via the formula.

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 description gives no guidance on when to use this tool versus alternatives, nor any conditions, prerequisites, or exclusions. The user must infer the usage context from the formula and the sibling tools, which is insufficient for a tool that might be selected among similar CFD calculations.

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