Nevermined Catalog

Search services

search_services

Read-only

Search the Nevermined Agent Services Catalog for paid services, ranked by ARD HYBRID relevance — semantic (meaning) matches merged with lexical (keyword) matches, most relevant first — falling back to pure lexical when the embedding provider is unavailable. Each result includes a closed matchReason, a per-item rankingSource, and one scale-specific score. A query is required; the other filters are optional. Returns matching listings (vendor, protocol, headlinePriceLabel, endpoints). headlinePriceLabel is derived from endpoint prices; "from" means prices vary. Budget against the selected endpoint price and quote before paying. Only the first page is returned: the pageToken in the result cannot be passed back to this tool, so to see other matches narrow the query or filters, or raise pageSize (up to 100). Discovery only; no payment. To have the platform PICK (and optionally pay) the single best service for a need instead of choosing yourself, use route_by_intent.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "query": "<query>"
    },
    "name": "search_services"
  }
}

Input Schema

Name	Required	Description
`tag`	No	Restrict to services carrying this catalog tag (e.g. a protocol or domain keyword from a listing's `tags`). Combined with `category` it widens the match to either value rather than narrowing it.
`query`	Yes	What you need, in plain language. REQUIRED. Ranked semantically AND lexically (hybrid), most relevant first — a query describing the need ("translate documents to German") matches on meaning, not only exact words, and also keyword-matches title, descriptions and tags. Falls back to keyword-only ranking when the embedding provider is unavailable.
`prefer`	No	Move this opaque catalog slug to the front when it matched the returned page; if it did not match, keep the normal ranked fallback.
`exclude`	No	Never return this opaque catalog slug in the result page.
`funding`	No	Only services with at least one endpoint payable with Nevermined credits. Local catalog only. Check get_service: the specific endpoint carries subscription when credits can pay it; this does not check your balance.
`category`	No	Restrict to services carrying this catalog tag — it filters on tags exactly like `tag`. The category names `list_categories` returns are not stored as tags, so passing one here matches nothing; put a category name in `query` instead. Given together, `category` and `tag` match a service carrying either one.
`pageSize`	No	Page size, 1–100 (a size of 0 is meaningless and is rejected).
`protocol`	No	Restrict to a payment protocol. Only x402 and mpp are payable via the Router.

Schema Changelog

Changes observed during successful MCP inspections.

Changed1 schema field changedNov 4, 2026

addedInput schema / properties / funding

Added value: +{
+  "description": "Only services with at least one endpoint payable with Nevermined credits. Local catalog only. Check get_service: the specific endpoint carries subscription when credits can pay it; this does not check your balance.",
+  "enum": [
+    "subscription"
+  ],
+  "type": "string"
+}

Changed1 schema field changedOct 21, 2026
- removedInput schema / additionalProperties
```
Removed value: -false
```

Changed2 schema fields changedSep 30, 2026

addedInput schema / properties / exclude

Added value: +{
+  "description": "Never return this opaque catalog slug in the result page.",
+  "minLength": 1,
+  "type": "string"
+}

addedInput schema / properties / prefer

Added value: +{
+  "description": "Move this opaque catalog slug to the front when it matched the returned page; if it did not match, keep the normal ranked fallback.",
+  "minLength": 1,
+  "type": "string"
+}

First observedSep 29, 2026

TDQS

A4.6/5.0

Behavior4/5

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

Annotations only declare readOnlyHint=true, and the description is consistent with a read-only search while adding real behavior: ranking degradation to keyword-only when the embedding provider is unavailable, and the significant constraint that the returned pageToken cannot be fed back in. The price-label semantics ("from" means prices vary) and the warning to budget against the selected endpoint price are useful operational context. Slightly short of 5 only because it does not describe result ordering edge cases or empty-result behavior beyond the fallback note.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Front-loaded with purpose and ranking model, then constraints, then the sibling alternative — a sensible order with no filler sentences. It is a dense single paragraph, however, and the return-field and pagination details could be split out for faster scanning.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

There is no output schema, so the description carries the return shape and does so (vendor, protocol, headlinePriceLabel, endpoints, matchReason, rankingSource, score). Combined with the annotation, the pagination limitation, and the payment boundary, an agent has everything needed to call it correctly and interpret results.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters4/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so the baseline is 3; the description still adds cross-parameter meaning — that pageSize caps at 100 and is the lever for seeing more matches, and that query is required while the rest are optional. It does not elaborate on prefer/exclude/funding/category/tag, which remain fully documented in the schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource ("Search the Nevermined Agent Services Catalog for paid services") plus the ranking model (ARD HYBRID semantic+lexical, with lexical fallback). It explicitly contrasts itself with the sibling route_by_intent, so an agent can pick between them without opening either schema.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines5/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

Names the alternative and the exact condition that selects it ("To have the platform PICK... use route_by_intent"), and states the boundary "Discovery only; no payment." It also gives concrete guidance for the pagination limitation (narrow the query or filters, or raise pageSize up to 100).

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

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