set_blueprint_variable_default

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

With no annotations, the description carries the behavioral burden and does well by disclosing the internal mechanism (FBPVariableDescription + CDO via ImportText) and the immediate-visibility effect without a full recompile. It does not mention failure modes or whether the asset must be saved afterward, but the disclosed behavior is substantial.

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 purpose is front-loaded in one clear sentence, followed by well-labeled Args, Returns, KB, and Example sections. Each part adds practical value, and the structure makes the definition easy to scan and use.

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 definition covers the operation, parameters, return shape, an example, and a KB pointer, which is strong for a 3-parameter tool. It is slightly incomplete on error semantics (e.g., unknown variable name, invalid default_value) and the default_value type example is inconsistent, but an agent can still invoke it correctly in most cases.

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?

All three parameters are individually documented with useful guidance, including examples for default_value ('42', 'true', vector syntax). The main flaw is that the example call passes default_value=0.0 as a bare float while the parameter description says it must be a string, creating ambiguity.

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 description opens with a specific verb and resource: 'Set the default value of a Blueprint member variable.' It further distinguishes itself from generic setters like set_blueprint_property by focusing on defaults and the FBPVariableDescription/CDO update path, so an agent can tell what this tool is for.

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 gives clear context for when this tool is appropriate: it updates both the FBPVariableDescription record and the CDO so changes are visible immediately without a full recompile. It does not explicitly name alternatives or state when not to use it, so it stops 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.