Trigger Custom Event

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

Beyond the annotations, the description discloses the exact RPN delivery syntax, the fact that this is not native SimConnect event mapping, and the important aircraft-specific no-op behavior with a concrete PMDG 737 example. This is rich behavioral context that the structured fields do not provide.

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?

Three focused paragraphs each serve a distinct purpose: definition, mechanism and alternative, and failure-mode caveat. The PMDG example is detailed but earns its place by explaining a non-obvious result an agent would otherwise misinterpret. There is no fluff.

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 tool with non-trivial runtime behavior, the description covers mechanism, prerequisite, alternative path, and failure interpretation. With full schema coverage and an output schema present, nothing essential is missing for an agent to invoke it correctly.

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 coverage is 100%, so the schema already documents both parameters and gives an example for `name`. The description adds genuine value by showing how `name` maps to `(>K:NAME)` and how `parameter` is prefixed when present, clarifying the runtime semantics beyond the schema.

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 first sentence states a specific action ('Fire a custom event as a key event') and a specific resource ('through the MobiFlight WASM module'). The second paragraph explicitly contrasts this with msfs_trigger_event, making the tool's distinct role in the sibling set clear.

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 names msfs_trigger_event as the native SimConnect alternative and explains that this path reaches events outside the standard SimConnect catalog, which helps an agent choose between them. It also flags the WASM module requirement. It stops short of an explicit 'use this when / use that when' rule, but the guidance is strong.

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