Bullrun

Search ETFs

search_etfs

Read-only

Find ETFs by name, ticker or ISIN and filter results by category, region, index, distribution policy, AUM, expense ratio or yield to locate a specific known fund.

Instructions

Look up ETFs by name, ticker or ISIN, with classification, listing, index, distribution-policy, AUM, expense-ratio and yield filters. Best for finding a known fund. For ranking questions ("cheapest", "largest", "best performing", "most liquid") prefer screen_etfs, which evaluates the whole universe: here minAum and minYieldTtmPct are applied only to a bounded profile-enriched candidate scan, so do not describe the result as exhaustive when candidateCapReached is true. Use get_etf_snapshot for one listing, get_etf_fund to resolve an ISIN across venues, and get_etf_holdings for constituents. Read-only.

Input Schema

Name	Required	Description	Default
`focus`	No	Exact ETF focus/exposure filter, e.g. Japan, TOPIX, or Equity - Australia.
`limit`	No	Maximum matching ETFs to return, 1-100.
`minAum`	No	Minimum assets under management in the profile's reported currency units.
`region`	No	Exact portfolio or investment-region filter.
`search`	No	Free-text ETF search by ticker, fund name, or ISIN (e.g. IE00B4L5Y983). Omit for a broad screen.
`sortBy`	No	Sort field. Relevance preserves Bullrun search ordering.	relevance
`category`	No	Exact broad ETF category/asset-class filter, e.g. Equity, Fixed Income, Commodity, Crypto, or Real Estate. Call get_etf_filter_options for valid values.
`currency`	No	Exact trading-currency filter.
`domicile`	No	Exact fund domicile filter.
`exchange`	No	Exact listing exchange filter.
`indexKey`	No	Exact tracked-index key, e.g. SP500 or MSCI_WORLD. Use get_etf_index_group to rank every fund on one index by cost.
`scanLimit`	No	Maximum coarse-search candidates to enrich before applying quantitative filters/sorts, 25-500.
`sortDirection`	No		desc
`minYieldTtmPct`	No	Minimum trailing yield in percentage points, e.g. 2 means 2%.
`includeInactive`	No
`includeSecondary`	No
`distributionPolicy`	No	Accumulating (reinvests income) or distributing (pays it out).
`maxExpenseRatioPct`	No	Maximum annual expense ratio in percentage points, e.g. 0.25 means 0.25%.

Output Schema

Name	Required	Description	Default
`query`	Yes
`results`	Yes
`webPage`	No
`coverage`	Yes
`returned`	Yes
`warnings`	Yes
`platformLink`	No
`matchesInScannedCandidates`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

Addedv0.7.0Oct 19, 2026

TDQS

A4.8/5.0

Behavior5/5

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

Annotations already declare readOnlyHint/destructiveHint, but the description adds genuinely non-obvious behavior: minAum and minYieldTtmPct are only applied to a bounded profile-enriched candidate scan, and results are not exhaustive when candidateCapReached is true. That is a real correctness caveat an agent cannot infer from the schema alone.

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?

Four sentences, front-loaded with what it does, then alternative routing, then the exhaustiveness caveat, then sibling pointers. No filler; the trailing 'Read-only' is mildly redundant with annotations but negligible.

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?

For an 18-parameter optional-filter tool with an output schema, the description supplies the routing and the one behavioral trap (bounded candidate scan). Minor gap: three parameters (includeInactive, includeSecondary, sortDirection) are undocumented in both schema and description, so an agent must guess their effect.

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 83%, so the baseline is 3; the description goes beyond by clarifying the scope of minAum/minYieldTtmPct (bounded candidate scan, not the whole universe) and by framing search as the free-text entry point vs. exact-match facet filters. It does not clarify includeInactive, includeSecondary or sortDirection, which lack schema descriptions.

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 (look up ETFs) plus the lookup keys (name, ticker, ISIN) and the filter families available, so an agent immediately knows this is a known-item lookup with faceted filtering, distinct from the screening and per-fund siblings.

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 says 'Best for finding a known fund', names screen_etfs as the alternative for ranking questions with quoted example queries ('cheapest', 'largest'), and routes single-listing, ISIN-resolution and constituents use cases to get_etf_snapshot, get_etf_fund and get_etf_holdings respectively. When-to-use, when-not-to-use and alternatives are all present.

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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