add_internal_shape

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

With no annotations, the description carries the behavioral burden and handles it well: it specifies pattern coordinates in mm, point type semantics (0, 2, 3), closed behavior, and even notes that CLO accepts points outside the piece. It does not discuss reversibility or validation errors, but the draw action and coordinate rules are clearly disclosed.

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 compact, front-loaded with the action, and uses an Args list that maps cleanly to the schema. No redundant or filler sentences.

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 create-style operation with no output schema and no annotations, the description covers the needed coordinate source, accepted point shapes, closure, and outside-piece behavior. An agent has enough to invoke the tool correctly without additional research.

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%, so the description must compensate, and it does: it explains the points array format including optional type codes, coordinate units, point type meanings, and the closed parameter's behavior. Pattern_index is also given a one-line role.

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 states a specific verb and resource, 'Draw an internal line or shape on a pattern', and gives concrete examples that clarify scope (fold lines, darts, pocket placement). This is distinguishable by 'internal' from other adding tools like topstitch or hem.

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 examples provide clear context for when the tool is appropriate, and the reference to get_pattern_geometry gives actionable guidance for obtaining coordinates. It does not explicitly name exclusions or alternatives such as add_topstitch, but the internal-shape framing makes selection fairly unambiguous.

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