call_custom_event

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

With no annotations, the description carries the behavioral burden. It explains what happens internally: 'resolves the target Blueprint generated class and returns visible pins for follow-up wiring.' It also implies mutation through 'Add a call node.' It could disclose more about failure modes or whether compilation/saving is required, but it provides meaningful behavior beyond the schema.

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 well-structured and front-loaded: purpose, usage timing, behavior, arguments, knowledge-base pointer, and example. Every section earns its place, and there is no redundant filler or repetition of schema titles.

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?

The combination of purpose, argument documentation, example, and cross-reference is enough for a 4-parameter graph-editing tool, especially with an output schema present. The main missing piece is a direct comparison to related siblings like call_event_dispatcher or add_blueprint_event_node, but the core invocation context is well covered.

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 0%, so the description fully compensates. Every parameter is explained in the Args section: blueprint_name as receiver, target_blueprint as owner, event_name as the custom event, and node_position as optional [X, Y]. The example also clarifies expected path formats and optionality.

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 and resource: 'Add a call node for a Custom Event defined on another Blueprint.' This clearly distinguishes it from siblings like add_custom_event (which defines an event) and call_event_dispatcher (which calls a dispatcher, not a custom event). An agent can infer what the tool does without opening the schema.

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?

Provides explicit usage context: 'Use this after creating or verifying the target custom event.' This gives a clear prerequisite and ordering constraint. It does not explicitly mention alternatives or exclusions relative to similar node-adding tools, so it falls short of a 5.

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