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

Annotations already declare destructiveHint=true and openWorldHint=false, so the safety bar is lower. The description adds meaningful side-effect context — attaching to a style affects every part in that style — but never warns that creation is destructive or what permissions/conflicts apply.

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?

Two tight sentences with no filler, and the core purpose is front-loaded. The second sentence could be split or bulleted to make the two attachment modes easier to scan, but nothing is wasted.

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, 5-required mutation tool with 13% schema coverage, no output schema, and a destructive hint, the description is thin. An agent learns what a piece is but not what the required templateId/partClassId/position mean or what a successful call returns.

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 only 13% across 8 parameters, so the description must compensate and largely does not. It clarifies the part-vs-style attachment semantics that map to part_id/style_id, but says nothing about svg, name, position, templateId, or the required vs optional nature of these fields.

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 and resource: 'Create a reusable SVG building block for a template and part class.' That distinguishes it from create_part, create_style, and create_template, though the domain terms 'piece' and 'part class' still require inference from the sibling list.

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 second sentence gives real conditional guidance for choosing between attaching to a part (part-specific content) versus a style (applies to every part in that style). However, it never says when a piece is the right object to create at all, nor any prerequisites, so usage is only implied at the tool level.

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