Lists and filters the roughly 220 Tweakers Vraag & Aanbod second-hand categories by matching case-insensitive text in slug or name, so users can find the right category.
List Vraag & Aanbod categories (about 220, e.g. laptops, videokaarten, cameras).
| Name | Required | Description | Default |
|---|---|---|---|
| contains | No | Case-insensitive text to match in slug or name. |
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds useful context about result volume (~220 entries) and the domain of category values, but says nothing about ordering, pagination, or how the 'contains' filter narrows the set.
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?
One sentence, front-loaded with the verb and resource, and every clause earns its place by adding cardinality and concrete examples. No filler or redundancy.
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, and the single parameter is fully covered by the schema. The remaining gap is minor: it doesn't say what happens with large unfiltered results.
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 100%, and the single 'contains' parameter is fully documented in the schema as a case-insensitive slug/name match. The description contributes nothing about the filter (e.g. that omitting it returns the full ~220 list), so 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 and resource ('List Vraag & Aanbod categories') and adds cardinality (~220) plus concrete examples (laptops, videokaarten, cameras), so an agent knows exactly what comes back. It does not explicitly contrast with search_listings or get_listing, so it stops short of a 5.
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 only implied: an agent can infer this is the lookup to call before filtering listings by category, but the description never says when to use it versus search_listings or get_listing. No prerequisites or exclusions are stated.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.