Primary Sources

hk_open_data_search

Read-onlyIdempotent

Search the Hong Kong government open-data catalogue DATA.GOV.HK (free, no key). Returns dataset titles, notes, organizations and resource download URLs. Use to discover HK datasets; use hk_open_data_filter to query a resource.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`rows`	No	Max datasets, default 10
`query`	Yes	Search terms, e.g. air quality

Output Schema

TableJSON Schema

Name	Required	Description
`data`	Yes	Source payload; fields vary per tool
`source`	Yes	Human-readable upstream source name
`retrievedAt`	Yes	ISO-8601 timestamp of retrieval

Schema Changelog

Changes observed during successful MCP inspections.

Changed3 schema fields changedOct 3, 2026

addedInput schema / properties / query / description
```
Added value: +"Search terms, e.g. air quality"
```
addedInput schema / properties / rows / description
```
Added value: +"Max datasets, default 10"
```

changedOutput schema / (root)

Previous value: -nullNew value: +{
+  "properties": {
+    "data": {
+      "description": "Source payload; fields vary per tool",
+      "type": "object"
+    },
+    "retrievedAt": {
+      "description": "ISO-8601 timestamp of retrieval",
+      "type": "string"
+    },
+    "source": {
+      "description": "Human-readable upstream source name",
+      "type": "string"
+    }
+  },
+  "required": [
+    "source",
+    "retrievedAt",
+    "data"
+  ],
+  "type": "object"
+}

First observedOct 3, 2026

TDQS

A4.5/5.0

Behavior4/5

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

Annotations already declare readOnly/openWorld/idempotent/non-destructive, so the safety profile is covered. The description adds non-obvious operational context — free, no API key required — and enumerates the returned fields. It does not mention rate limits or pagination behavior, so it falls short of a 5.

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

Conciseness5/5

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

Three short clauses with zero waste: what it is, what it returns, and when to prefer the sibling. Scoping information is front-loaded and the routing hint comes last.

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?

An output schema exists, so return-value explanation is optional and the brief field list is a bonus. Coverage of source, cost, return shape, and the alternative tool is sufficient for an agent to call this correctly.

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

Parameters3/5

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

Schema description coverage is 100%, so both parameters (query, rows) are already documented with examples and defaults in the schema. The description adds no parameter-level detail beyond that, making the baseline 3 appropriate.

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 (Search) and resource (Hong Kong government open-data catalogue DATA.GOV.HK) and names the sibling it is not (hk_open_data_filter). An agent can distinguish it from the ~48 other search tools without opening a 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?

Explicitly gives both sides: use this to discover HK datasets, use hk_open_data_filter to query a resource. The condition that selects the alternative is stated, not inferred.

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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