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

Annotations already establish read-only, idempotent, non-destructive behavior, lowering the burden on the description. The description adds useful behavioral context by mentioning per-category counts and that categories can be passed as search queries, going beyond what the annotation block alone provides.

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 with no filler: the first states the core action and output characteristic, and the second provides usage guidance for the related sibling tool. Every sentence earns its place.

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 required enum parameter, full schema coverage, an output schema, and safety annotations, nothing needed to call the tool correctly is missing. The description also covers the likely next step by connecting categories to assets_search.

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?

The single 'type' parameter is fully documented in the schema with an enum and a clear description, so the description doesn't need to add much. The phrase 'for an asset type' maps to that parameter but adds no format or value detail beyond the schema.

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 states a specific action ('List'), a concrete resource ('Poly Haven categories'), and a scope ('for an asset type'), plus a distinguishing detail ('per-category counts'). It also references assets_search, making clear this tool is for browsing the category taxonomy rather than searching assets.

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 gives a clear follow-up directive: 'Pass a category as the assets_search query to filter,' which tells the agent when to hand off to assets_search. It does not explicitly enumerate exclusion conditions like 'use only when you need categories,' so the guidance is strong but not fully explicit.

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