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

Annotations already declare idempotentHint=true, destructiveHint=true, and readOnlyHint=false, so the safety profile is covered. The description adds real value beyond that by naming 'optimistic concurrency' (hinting at expectedRevision conflict behavior) and an 'idempotent mutation receipt', but it never states what a destructive update overwrites or what happens on revision conflict.

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?

A single tight sentence with the core action front-loaded and zero padding. Its brevity is a virtue structurally, though it leaves content gaps addressed in other dimensions.

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 12-parameter destructive mutation with 25% schema coverage, the description is under-specified: it omits how create-vs-update is selected, the default workspace behavior, and any conflict-resolution detail. The output schema covers returns, but the inputs and mode selection remain thin.

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 25% across 12 parameters, so the description must compensate and largely does not. 'Optimistic concurrency' and 'idempotent mutation receipt' gesture at expectedRevision and idempotencyKey, but name, visualStyle, workspaceId, storyKitId, and the locations/facts structures get no clarification beyond the thin schema text.

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 pair (create or update) and the resource (Story Kit), which cleanly separates it from story_kits_get and story_kits_list. It does not name those siblings explicitly, so it falls short of a 5, but the intent is immediately clear.

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?

No guidance on when to create versus update (presumably storyKitId presence), no prerequisites, no mention of the get/list siblings, and no exclusions. The agent must infer the mode from the schema alone.

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