list_families

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

With no annotations, the description fully discloses key behaviors: the return fields (family_name, type_name, category, activation status), the case-insensitive substring filtering, the limit/default, and the special meaning of an empty result. It also notes that placement fails on near-miss names, which is important context. No annotation contradiction exists.

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: a one-sentence primary purpose, followed by return field details and usage caveats, then parameter definitions. Every sentence contributes new, non-redundant information. It is long enough to be comprehensive yet remains tight and scannable.

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?

Despite lacking an output schema, the description clarifies the return format, edge cases (empty list), exclusions (system types), and integration with placement. For a list tool with two simple parameters, this covers all necessary context for correct invocation and interpretation.

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%, but the description provides full parameter semantics in the Args section: 'contains' is defined as a case-insensitive substring filter matched against family and type name, with omission behavior, and 'limit' is described as maximum results with a default of 50. This compensates completely for the schema's lack of descriptions.

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 clearly states the tool's function: 'List loadable family types available in the current model.' It identifies the specific resource (family types) and scope (current model), and further distinguishes from system types, making it unambiguous. This separates it from sibling tools like list_family_categories or list_levels.

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?

Explicit guidance is given: 'Call this before place_family to get exact names - placement fails on a near-miss.' It also explains that an empty list is a successful answer, and clearly states what the tool does NOT list (system types) and where those are reported (error messages of create_line_based_element or create_surface_based_element), providing clear alternatives.

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