set_pin_default_value

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

Annotations cover only the safety profile (destructive, idempotent, not read-only); the description adds substantial behavioral context beyond them: struct canonicalization of bare GameplayTag names, up-front rejection of unregistered tags, refusal of split/array pins, and the read-back oracle semantics ('a rejected value shows up as the old one'). That last point is critical for an agent interpreting a silent failure.

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?

Front-loaded with the core action and read-back oracle, then caveats, then the TRAP. Dense but nearly every sentence carries load. Minor cost: long run-on clauses and heavy uppercase emphasis reduce scannability slightly.

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 an 8-parameter mutation tool with no output schema, the description supplies the return shape ({ node_id, pin_name, default_value }), the PIE-restriction consequence, and the failure-mode interpretation. An agent has enough to call it and to detect when it silently did not take effect.

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 already 100%, so the baseline is 3. The description still adds meaning: value_json is 'the only way to put SEVERAL tags in a GameplayTagContainer' and 'takes precedence over value', plus the note that a plain string is acceptable for an FText pin. Some overlap with the schema's own value_json text, but precedence and capability notes are additive.

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+scope: 'Write the literal default of an UNCONNECTED input pin and return the value read BACK off the pin.' The uppercase qualifiers (UNCONNECTED, input pin) precisely delimit the operation, and the read-back promise immediately signals this is a write-with-verification, not a plain setter.

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?

Gives explicit refusal conditions and routes to alternates: array/set/map pins -> use a MakeArray/MakeSet/MakeMap node; split pins -> recombine_blueprint_pin first; FormatText Format pin -> build with Concat_StrStr/Conv_StringToText. It does not differentiate at the tool level from nearby setters (e.g. set_rigvm_pin_default, set_bp_variable_default), but the in-scope exclusions are unusually thorough.

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