design_add_symbol

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

With no annotations, the description carries the full burden. It usefully discloses side effects—resolving SVG path data, caching it in the sketch file, and auto-adding the symbol-draw component—but omits error behavior, return value, and whether existing symbol instances are affected.

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?

Three short sentences, front-loaded with purpose, then behavior, then automatic component addition. Every sentence contributes useful information without repetition or filler.

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 mutation tool with no annotations or output schema, the description gives the key side effects but omits the working context (which sketch is targeted), placement behavior, and error handling. It is adequate but not complete.

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 100%, so parameter meaning is already fully documented. The description does not add syntax, constraints, or defaults beyond what the schema provides, which is the baseline expectation when the schema is rich.

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 uses a specific verb and resource—'Add a symbol from the registry to a sketch'—and adds meaningful scope (registry symbol, not a generic shape). It is clear, but it does not explicitly differentiate itself from adjacent siblings such as design_place_symbol or design_fetch_symbol.

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?

It states what the tool does but gives no guidance on when to use it versus alternatives like design_place_symbol or design_fetch_symbol, and no prerequisites such as needing an open sketch. The agent is left to infer usage entirely.

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