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

Annotations already cover readOnly, non-destructive, and closed-world, so the 'Read-only: it saves nothing' sentence is largely redundant. However, the description adds genuinely new behavioral content beyond the annotations: the return values are design ids specifically formatted for create_draft, which is the key integration detail an agent needs.

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 sentences, front-loaded with the primary action and both modes, with no padding. The trailing 'Read-only: it saves nothing' is the one clause that duplicates annotations, a minor cost.

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?

With one optional parameter, no output schema, and full schema description coverage, the description supplies what's missing: the shape of returned data (design ids) and its downstream use. Only the exact return structure (fields besides id) is left implicit, which is acceptable for a browse tool.

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 100%, so the occasion parameter and its dual-mode behavior are already fully documented in the schema. The description restates the same dual-mode semantics at the tool level, reinforcing rather than extending what the schema provides. Baseline 3 applies.

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 (list) and two clearly delineated resources (occasions, card designs for one occasion), and distinguishes this from the sibling create_draft by naming it as the consumer of the returned design id. An agent can tell exactly what this returns without opening the schema.

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?

Usage is clear from context: call without occasion to discover valid occasion ids, then call again with one to get design ids for create_draft. There is no explicit statement of when not to use it or which sibling to prefer for a different need, so it stops short of full routing guidance.

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