Get a market-wide summary of institutional exposure to US spot crypto ETFs (Bitcoin ETF complex: IBIT, FBTC, GBTC, etc.) from the latest quarter of SEC 13F filings. Returns total institutional USD held, quarter-over-quarter change, and a per-ETF breakdown (holders, USD, QoQ).
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
| Name | Required | Description | Default |
|---|---|---|---|
| complex | Yes | ||
| products | Yes |
Changes observed during successful MCP inspections.
Output schema / (root)Previous value: -nullNew value: +{
+ "$schema": "http://json-schema.org/draft-07/schema#",
+ "additionalProperties": false,
+ "properties": {
+ "complex": {
+ "additionalProperties": false,
+ "properties": {
+ "products": {
+ "anyOf": [
+ {
+ "type": "integer"
+ },
+ {
+ "type": "null"
+ }
+ ]
+ },
+ "qoq_change": {
+ "$ref": "#/properties/complex/properties/total_usd"
+ },
+ "total_usd": {
+ "anyOf": [
+ {
+ "pattern": "^-?\\d+(\\.\\d+)?([eE][-+]?\\d+)?$",
+ "type": "string"
+ },
+ {
+ "type": "null"
+ }
+ ],
+ "description": "Exact decimal string as served by ko.io (not rounded); null = unknown"
+ }
+ },
+ "required": [
+ "total_usd",
+ "qoq_change",
+ "products"
+ ],
+ "type": "object"
+ },
+ "products": {
+ "items": {
+ "additionalProperties": false,
+ "properties": {
+ "holders": {
+ "$ref": "#/properties/complex/properties/products"
+ },
+ "prev_usd": {
+ "$ref": "#/properties/complex/properties/total_usd"
+ },
+ "product_name": {
+ "$ref": "#/properties/products/items/properties/product_ticker"
+ },
+ "product_ticker": {
+ "type": [
+ "string",
+ "null"
+ ]
+ },
+ "qoq_change": {
+ "$ref": "#/properties/complex/properties/total_usd"
+ },
+ "sponsor": {
+ "$ref": "#/properties/products/items/properties/product_ticker"
+ },
+ "total_usd": {
+ "$ref": "#/properties/complex/properties/total_usd"
+ }
+ },
+ "required": [
+ "product_ticker",
+ "product_name",
+ "sponsor",
+ "holders",
+ "total_usd",
+ "prev_usd",
+ "qoq_change"
+ ],
+ "type": "object"
+ },
+ "type": "array"
+ }
+ },
+ "required": [
+ "complex",
+ "products"
+ ],
+ "type": "object"
+}Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, and destructiveHint=false, so the tool is clearly safe and non-mutating. The description adds meaningful behavioral context by specifying that it returns data from the latest quarter (with no lookback control) and includes a per-ETF breakdown, QoQ change, and total USD, which helps set expectations about the output granularity.
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?
The description is a single concise sentence that front-loads the core purpose, then lists the exact return components. Every phrase earns its place, with no filler or redundant repetition of the tool name.
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?
For a parameterless tool that returns a known summary, the description is complete. It specifies the ETF complex (IBIT, FBTC, GBTC), the data source (SEC 13F), and the output fields (total USD, QoQ change, per-ETF breakdown). Additionally, an output schema exists, so the description doesn't need to further detail return values. There are no gaps that would prevent correct invocation.
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?
The tool has 0 parameters, so the description doesn't need to explain parameters. It instead clarifies what data is returned (total institutional USD, QoQ change, per-ETF breakdown), which is valuable for an agent deciding if this tool meets the query needs. With no parameters, the description's return details compensate well for the lack of schema guidance.
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?
The description states a specific verb ('Get') and resource ('US spot crypto ETFs') and clearly distinguishes it from siblings like 'get_crypto_holder' and 'get_crypto_holders' by focusing on a market-wide summary rather than individual holder data. It also specifies the data source (SEC 13F filings) and the scope (latest quarter), which removes ambiguity.
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?
The description clearly indicates when to use this tool (when needing a market-wide institutional exposure summary) but does not explicitly mention when not to use it or point to alternatives like 'get_crypto_holder' or 'get_crypto_holders' for granular per-entity data. The context is clear enough for an agent to infer the right choice, but explicit exclusions are missing.
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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