Merit Value

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

No annotations provided, so the description carries the full burden. It says 'current' which implies reading live state, but doesn't disclose whether the merit function must exist, whether it requires an open lens file, whether the value is cached, or what happens if no merit function is defined. A read-only query with no annotations should state its preconditions.

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 clear sentence, front-loaded with the verb. No waste.

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 no-parameter, no-annotation, no-output-schema tool in a family with several merit-function siblings, the definition is too thin. It should at least clarify the precondition (existing merit function/lens) and distinguish the 'current value' from zemax_get_merit_function.

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?

Zero parameters, so the schema burden is nil and the baseline is 4. The description doesn't need to explain parameters, and it correctly implies no inputs are required.

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+resource: 'Calculate the current merit-function value.' The agent knows exactly what it does. It doesn't differentiate from siblings like zemax_get_merit_function or zemax_forbes_merit_function, but the action ('calculate value') versus 'get function' implies a distinction.

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 use this versus alternatives like zemax_get_merit_function. The description gives no context about when the agent would want the current value, no exclusions, no prerequisites.

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