add_set_union_node

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

With no annotations, the description carries the full burden; it does clearly state that the tool adds a node and that the node combines sets and removes duplicates. However, it never discloses graph-mutation side effects, prerequisites (e.g., blueprint must exist), or what changes the operation makes to the existing graph, and 'Returns a new set' blurs the node's runtime semantics with the tool's own return.

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 core behavior is front-loaded in the first line, followed by a compact args list, KB pointer, and example. 'From Ch. 13:' is minor provenance noise but does not significantly bloat the description.

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 two-parameter graph-node tool, the description covers the operation, both parameters, a KB reference, and an example call. Since an output schema exists, explaining the return value is unnecessary; the main remaining gap is missing prerequisites or behavioral caveats.

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 0%, but the description compensates by documenting both parameters: 'blueprint_name: Blueprint to add the node to' and 'node_position: [X, Y] graph position.' It adds meaning beyond the raw schema, though it could clarify optionality/coordinate units.

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 — 'Add a Set UNION node' — and defines the operation as 'combine two sets (removes duplicates).' This distinguishes it from sibling set operations like intersection and difference, even without naming them.

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?

Usage context is implied by the set-union semantics and the example call, but no explicit when-to-use or when-not-to-use guidance is given, and no alternative tool is named despite many set-node siblings existing. The Ch. 13 reference provides context but does not define selection criteria.

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