Get Mtf Units

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

No annotations are provided, so the description carries the full burden, and it discloses only that a value is fetched. It does not say whether this reads a lens/system setting, what the returned unit identifier looks like (e.g. cycles/mm vs cycles/mrad), or whether any session state is required.

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 with no filler. Nothing could be removed without losing the tool's identity.

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 trivial no-argument getter this is nearly adequate, but with no output schema the description never states what form the returned unit takes, which is the one piece of information a caller of a 'get units' tool actually needs.

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; the baseline for a parameterless tool 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 ('Get') and resource ('MTF spatial-frequency units'), which is enough to separate it from the sibling setter zemax_set_mtf_units. It is slightly cryptic about what 'MTF units' concretely means (the unit convention used for MTF spatial frequency), but the read direction and target setting are unambiguous.

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?

No guidance on when to call this versus alternatives, and no mention of the paired setter zemax_set_mtf_units or of the MTF analysis tools whose output this setting governs. Usage must be inferred entirely from the name.

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