list_categories

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

No annotations are provided, so the description carries full burden. It's clearly a read-only list operation, but the description doesn't state that explicitly or describe rate limits, caching, or pagination. It mentions the same IDs work on both sites, which is useful cross-site context, but nothing about behavior beyond that.

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?

Very concise, two short sentences. Front-loaded with the main purpose. The second sentence about IDs working across sites is useful but could be integrated more clearly. No wasted words.

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 an output schema present, return values needn't be explained. However, for a reference tool with no annotations and an undocumented parameter, the description is minimal. It doesn't explain what 'main categories and common subcategories' look like or how to use them, nor does it clarify the site parameter's effect. Adequate but incomplete.

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 0% and there's 1 parameter ('site' with default 'marktplaats'). The description mentions 'marktplaats.nl and 2dehands.be' which implies the site parameter controls platform, but it doesn't map the parameter values to the domains or explain the default. This adds marginal value but leaves the parameter's enum/usage ambiguous.

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 resource (categories/subcategories) with clear scope. Distinguishes itself from siblings like get_category_filters which presumably returns filters for a category, and from search_listings. The description makes it clear this is a reference/list tool.

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 explicit when-to-use guidance or alternatives are named. The description implies it's a reference tool for discovering categories before searching, but it doesn't say when to use it vs get_category_filters or search_listings. No prerequisites or exclusions stated.

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