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

Goes beyond the annotations by disclosing that it 'Writes one draft version', that changes are reversible via 'as-designed ... to put the original back', and that an empty call is a pure read. These are real behavioral facts annotations cannot convey. Missing: what happens on a list node that is not a collection list, or whether the draft must be published afterward.

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?

One long sentence with nested parentheticals that reference the tool by its own name makes it hard to parse on first read. The core verb is front-loaded, but the recursion and stacked clauses cost the reader effort that a short bulleted split would have avoided.

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 output schema and no readOnly annotation, this covers the safety story (non-destructive, reversible, draft-only) and the discovery path. The main gap is that the draft/publish lifecycle and the 'library design' discovery flow (an empty call returns design ids) are only implied, not spelled out in sequence.

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?

With 75% schema coverage the schema already documents most fields, yet the description still adds value by naming the two design families (library designs, plain arrangements such as image-top/overlay) and enumerating the style dimensions (surface, corners, padding, photo shape, text alignment, hover). It does not explain what any individual style enum value visually does, so an agent must guess between 'border'/'shadow'/'filled'.

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?

Opens with a specific verb and resource plus scope: 'Change how every card of a collection list looks, in one call'. The two-parameter split (design swaps whole card, style adjusts it) is clearly stated. It loses a point for the circular phrase 'a library design from set_card_design (with no design)', which forces the reader to reconstruct meaning from itself.

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?

Explicitly routes away from the tempting alternative: 'Prefer this to rewriting a card template with patch_nodes/insert_nodes ... it cannot drop a field, break the card's link or lose the way back', and gives the reason. It also defines a discovery mode ('With neither design nor style it changes nothing and returns the designs and style choices'), so an agent knows how to explore before mutating.

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