Basis

screener_run

Read-onlyIdempotent

Scan the venue's listed instruments for ones matching conditions, instead of looking at the open chart. Rules combine price fields, any indicator plot, or a formula expression, with ALL/ANY matching. This is the tool for "which coins are doing X right now". It fetches history for every instrument in the universe, so use exactly the requested filters. For "5 coins with RSI above 50", call rules: [{left:{kind:"indicator",studyId:"rsi"},operator:"above",right:50}], limit:5. Use above for a current state; crossesAbove only for a fresh crossing. limit controls returned matches, universeSize controls how many markets are searched.

Input Schema

Name	Required	Description
`name`	No
`limit`	No	Matches to return. Default 25, max 60.
`logic`	No	Default all.
`order`	No	With sortBy. Default desc; asc for the biggest losers.
`quote`	No	Default USDC on Hyperliquid, USDT elsewhere.
`rules`	Yes
`market`	No	Defaults to the chart. Perpetuals are futures.
`sortBy`	No	Order the matches before the limit, e.g. change24h for top movers. Default: universe order (volume).
`exchange`	No	Defaults to the chart.
`lookback`	No	Bars. Default 300.
`timeframe`	No	Defaults to the chart.
`universeSize`	No	Default 50.
`manualSymbols`	No	Optional symbols forced into the universe before current-volume ranking.

Schema Changelog

Changes observed during successful MCP inspections.

Changed4 schema fields changedOct 23, 2026

changedInput schema / properties / quote / description

Previous value: -"Default USDT."New value: +"Default USDC on Hyperliquid, USDT elsewhere."

addedInput schema / properties / rules / items / properties / left / properties

Added value: +{
+  "expression": {
+    "type": "string"
+  },
+  "field": {
+    "enum": [
+      "open",
+      "high",
+      "low",
+      "close",
+      "volume",
+      "quoteVolume",
+      "trades",
+      "change1",
+      "change5",
+      "rangePercent"
+    ],
+    "type": "string"
+  },
+  "kind": {
+    "enum": [
+      "field",
+      "indicator",
+      "formula",
+      "strategy"
+    ],
+    "type": "string"
+  },
+  "name": {
+    "type": "string"
+  },
+  "parameters": {
+    "additionalProperties": {
+      "type": "number"
+    },
+    "type": "object"
+  },
+  "params": {
+    "additionalProperties": {
+      "type": [
+        "number",
+        "string",
+        "boolean"
+      ]
+    },
+    "type": "object"
+  },
+  "plotKey": {
+    "description": "Optional; defaults to the first indicator output.",
+    "type": "string"
+  },
+  "strategyId": {
+    "type": "string"
+  },
+  "studyId": {
+    "description": "Indicator id, e.g. rsi or ema.",
+    "type": "string"
+  }
+}

addedInput schema / properties / rules / items / properties / right / anyOf

Added value: +[
+  {
+    "type": "number"
+  },
+  {
+    "properties": {
+      "kind": {
+        "enum": [
+          "constant",
+          "operand"
+        ],
+        "type": "string"
+      },
+      "operand": {
+        "properties": {
+          "expression": {
+            "type": "string"
+          },
+          "field": {
+            "type": "string"
+          },
+          "kind": {
+            "enum": [
+              "field",
+              "indicator",
+              "formula",
+              "strategy"
+            ],
+            "type": "string"
+          },
+          "params": {
+            "type": "object"
+          },
+          "plotKey": {
+            "type": "string"
+          },
+          "strategyId": {
+            "type": "string"
+          },
+          "studyId": {
+            "type": "string"
+          }
+        },
+        "type": "object"
+      },
+      "value": {
+        "type": "number"
+      }
+    },
+    "type": "object"
+  }
+]

changedInput schema / properties / rules / items / properties / right / description

Previous value: -"A number, or another operand in the same form as left."New value: +"Use a number for a threshold: RSI >50 is {left:{kind:\"indicator\",studyId:\"rsi\"},operator:\"above\",right:50}. To compare with an indicator use {kind:\"operand\",operand:{kind:\"indicator\",studyId:\"ema\",params:{period:20}}}."

Changed4 schema fields changedOct 17, 2026

addedInput schema / properties / exchange

Added value: +{
+  "description": "Defaults to the chart.",
+  "enum": [
+    "binance",
+    "bybit",
+    "okx",
+    "hyperliquid"
+  ],
+  "type": "string"
+}

addedInput schema / properties / market

Added value: +{
+  "description": "Defaults to the chart. Perpetuals are futures.",
+  "enum": [
+    "spot",
+    "futures"
+  ],
+  "type": "string"
+}

addedInput schema / properties / order

Added value: +{
+  "description": "With sortBy. Default desc; asc for the biggest losers.",
+  "enum": [
+    "desc",
+    "asc"
+  ],
+  "type": "string"
+}

addedInput schema / properties / sortBy

Added value: +{
+  "description": "Order the matches before the limit, e.g. change24h for top movers. Default: universe order (volume).",
+  "enum": [
+    "change24h",
+    "volume24h"
+  ],
+  "type": "string"
+}

Changed2 schema fields changedOct 11, 2026

changedInput schema / properties / rules / items / properties / right / description

Previous value: -"{\"kind\":\"constant\",\"value\":30} or {\"kind\":\"operand\",\"operand\":{…}}"New value: +"A number, or another operand in the same form as left."

removedInput schema / properties / rules / items / properties / right / type
```
Removed value: -"object"
```

First observedSep 20, 2026

TDQS

A4.2/5.0

Behavior4/5

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

Annotations already cover safety (readOnly, idempotent, non-destructive), so credit goes to what the text adds: a cost hint that it 'fetches history for every instrument in the universe', plus the note that several params default to the current chart's setting. It does not describe pagination or performance limits on large universes.

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

Conciseness4/5

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

Front-loaded with the core purpose and followed by progressively more specific guidance; each sentence carries information. Slightly padded by restating schema defaults ('Defaults to the chart') inline, which lengthens the prose without new meaning.

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

Completeness3/5

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

For a 13-parameter tool with a nested rules grammar and no output schema, the description never says what a match actually contains (symbol + which values, how the matched rule is reported). Rules-construction and universe sizing are well covered, but the shape of results remains an inference for the agent.

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 85%, so the baseline would be 3, but the description adds real semantic value the schema lacks: the limit vs universeSize distinction ('limit controls returned matches, universeSize controls how many markets are searched') and a concrete worked example for rules with an indicator operand. The above/crossesAbove operator guidance also disambiguates an enum the schema leaves bare.

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 (scan) and resource (the venue's listed instruments), and explicitly contrasts scope with 'looking at the open chart', which separates it from the chart_* and indicator_compute siblings. The phrase 'which coins are doing X right now' nails the intent in an agent-legible way.

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

Usage Guidelines4/5

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

Gives clear invocation context ('which coins are doing X right now') and a decision rule for the trickiest choice: 'Use above for a current state; crossesAbove only for a fresh crossing.' It never names a sibling alternative (e.g. screener_backtest, daytrade_opportunity_scan) or states when not to use it, so it stops short of a 5.

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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