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

Annotations already declare destructiveHint=true and idempotentHint=true, so the safety profile is known. The description adds genuinely useful context beyond that: it explains what is overwritten ('Replaces cached previews at deterministic storage keys') and what is preserved ('preserves the source project and slide document'), which is exactly the mutation impact 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 tight sentences with zero waste, front-loading the core action and then the storage/impact detail. Nothing is redundant.

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?

An output schema exists so return values need not be explained, and the destructive/idempotent behavior is well covered. However, with 5 parameters and only 20% schema coverage, the description leaves the enumeration and selection parameters (chrome, slideIndexes) unexplained.

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 20% (just projectId's 'UUID string'), and the description does not compensate. Key params like 'chrome' (tiktok/instagram/none), 'slideIndexes', 'workspaceId', and the required 'idempotencyKey' are undocumented in either place, leaving their semantics opaque.

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 ('Render and store') plus resource and scope ('private JPEG previews for the selected carousel slides'). It clearly distinguishes a preview-generation action from siblings like carousels_apply_template or carousels_compile, though it doesn't name those alternatives.

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 use this versus carousels_get, carousels_compile, or other carousel tools, and no prerequisites or exclusions are stated. The agent must infer the usage context entirely.

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