Open Economics

Query official CVM investment-fund reports

get_cvm_investment_funds

Read-onlyIdempotent

Retrieve daily CVM aggregates by official fund classification or resolve a fund/class latest report by CNPJ or name. Net assets and flows are additive; quota values stay fund-level; reported holder totals are not deduplicated people.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`to`	No	Inclusive last report date, YYYY-MM-DD.
`from`	No	Inclusive first report date, YYYY-MM-DD.
`funds`	No	Unformatted 14-digit fund/class CNPJ values.
`limit`	No	Maximum fund or classification rows to return.
`query`	No	Fund-name search; use only with breakdown=fund.
`breakdown`	No	Whether to aggregate by official classification or resolve a fund.	classification
`dataset_id`	Yes	The official CVM investment-funds dataset identifier.
`classifications`	No	Official fund classifications to include.

Output Schema

TableJSON Schema

Name	Required	Description
`data`	Yes	Source-preserving data or schema payload for the selected official dataset.
`meta`	Yes	Response metadata and source provenance.
`links`	No	Related API links.

Schema Changelog

Changes observed during successful MCP inspections.

Changed7 schema fields changedSep 11, 2026

addedInput schema / properties / breakdown / description

Added value: +"Whether to aggregate by official classification or resolve a fund."

addedInput schema / properties / classifications / description
```
Added value: +"Official fund classifications to include."
```

addedInput schema / properties / dataset_id / description

Added value: +"The official CVM investment-funds dataset identifier."

addedInput schema / properties / from / description

Added value: +"Inclusive first report date, YYYY-MM-DD."

addedInput schema / properties / limit / description

Added value: +"Maximum fund or classification rows to return."

addedInput schema / properties / to / description

Added value: +"Inclusive last report date, YYYY-MM-DD."

changedOutput schema / (root)

Previous value: -nullNew value: +{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "additionalProperties": {},
+  "description": "REST-aligned Open Economics response with data, metadata, links, and source provenance.",
+  "properties": {
+    "data": {
+      "description": "Source-preserving data or schema payload for the selected official dataset."
+    },
+    "links": {
+      "additionalProperties": {},
+      "description": "Related API links.",
+      "properties": {
+        "observations": {
+          "description": "Canonical observations endpoint for this dataset.",
+          "type": "string"
+        },
+        "self": {
+          "description": "Canonical URL for this response.",
+          "type": "string"
+        }
+      },
+      "type": "object"
+    },
+    "meta": {
+      "additionalProperties": {},
+      "description": "Response metadata and source provenance.",
+      "properties": {
+        "dataset": {
+          "description": "Open Economics dataset identity when supplied."
+        },
+        "provenance": {
+          "description": "Upstream source URLs, versions, timestamps, and methodology details."
+        }
+      },
+      "type": "object"
+    }
+  },
+  "required": [
+    "data",
+    "meta"
+  ],
+  "type": "object"
+}

First observedSep 9, 2026

TDQS

A4.2/5.0

Behavior4/5

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

Annotations already declare readOnly, idempotent, non-destructive, non-open-world, so the safety profile is covered. The description adds genuinely useful data-semantics beyond that: net assets and flows are additive across rows, quota values are fund-level only, and holder totals are not deduplicated — non-obvious interpretation caveats an agent would otherwise get wrong.

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?

Two sentences, no filler. The primary retrieval modes are front-loaded, with the data caveats packed into a compact trailing clause. Every phrase carries information.

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

Completeness4/5

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

With an output schema present, return-shape explanation is unnecessary, and the description covers both operating modes plus the key interpretation pitfalls. What is missing is small routing guidance — when to reach for the schema sibling or the search tool — but for an 8-parameter read tool this is close to complete.

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 description coverage is 100%, so the baseline is 3, and the description earns an extra point by explaining what breakdown actually selects and by clarifying the aggregation-level semantics that the schema only states mechanically ('aggregate by official classification or resolve a fund'). It still does not speak to limit defaults or the maxItems caps.

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 two concrete verbs and resources: 'Retrieve daily CVM aggregates by official fund classification' and 'resolve a fund/class latest report by CNPJ or name.' The two modes map cleanly onto the breakdown enum, and the sibling get_cvm_investment_funds_schema is clearly the schema companion rather than a competitor.

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

Usage Guidelines3/5

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

The description implies that aggregation vs. single-fund resolution is chosen by which lookup key you supply (classification vs. CNPJ/name), and the schema notes query is only valid with breakdown=fund. But there is no explicit when-to-use guidance, no mention of when to prefer the schema sibling, and no stated prerequisites or exclusions.

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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