list_superinvestorsThe investors Talval tracks through their quarterly 13F filings — portfolio size, position count and largest holdings.
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
| Name | Required | Description | Default |
|---|---|---|---|
| investors | Yes |
Changes observed during successful MCP inspections.
Output schema / (root)Previous value: -nullNew value: +{
+ "properties": {
+ "investors": {
+ "items": {
+ "properties": {
+ "manager": {
+ "type": [
+ "string",
+ "null"
+ ]
+ },
+ "n_positions": {
+ "type": [
+ "integer",
+ "null"
+ ]
+ },
+ "person": {
+ "type": [
+ "string",
+ "null"
+ ]
+ },
+ "portfolio_value_usd": {
+ "type": [
+ "number",
+ "null"
+ ]
+ },
+ "quarter_end": {
+ "description": "The reported quarter, YYYY-MM-DD.",
+ "type": [
+ "string",
+ "null"
+ ]
+ },
+ "slug": {
+ "description": "Pass this to get_superinvestor.",
+ "type": "string"
+ }
+ },
+ "required": [
+ "slug"
+ ],
+ "type": "object"
+ },
+ "type": "array"
+ }
+ },
+ "required": [
+ "investors"
+ ],
+ "type": "object"
+}Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so the safety profile is covered. The description adds genuine context beyond that — the data source and implied timeliness ('quarterly 13F filings') and the shape of what each entry carries (portfolio size, position count, largest holdings). It does not, however, mention freshness lag or coverage limits.
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?
A single sentence with no filler, and the datasource qualifier is front-loaded. It is efficient, though the missing verb is a structural omission rather than verbosity — the agent may, however, want to know this comes from a list operation rather than a lookup.
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?
A rich output schema exists (so return values need not be explained) and annotations carry the safety profile, so the burden on the description is light. Still, the absence of any stated operation or sibling routing leaves a gap around why an agent should pick this over get_superinvestor.
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 takes zero parameters, so there is nothing for the description to disambiguate; the baseline for a parameterless tool applies. The description correctly avoids inventing optional filters.
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 is a noun phrase describing what a superinvestor is ('investors Talval tracks through their quarterly 13F filings'), but it never states the verb — that the tool returns a list. It partially restates the title and offers no differentiation from the sibling get_superinvestor, so the agent must infer the operation.
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?
There is no indication of when to call this versus get_superinvestor (single investor lookup) or the other screen_/search_ siblings. No prerequisites, no exclusions, and no context are given — usage must be inferred entirely from the name.
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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