PerfLens MCP Server

Overview Schema Source Related Servers Discussions Admin

get_call_paths

Read-onlyIdempotent

Retrieve a paginated list of dominant call paths from a performance analysis, optionally filtered by a symbol, to locate bottlenecks.

Instructions

Return a bounded page of dominant call paths, optionally containing a symbol.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`limit`	No
`cursor`	No
`symbol`	No
`analysis_id`	Yes

Output Schema

TableJSON Schema

Name	Required	Default
`items`	Yes
`symbol`	Yes
`analysis_id`	Yes
`next_cursor`	No
`total_items`	Yes
`schema_version`	No	1.0
`evidence_quality`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

Changed12 schema fields changedv0.3.2Aug 28, 2026

addedOutput schema / $defs / EvidenceQuality / properties / kernel_context_self_percent

Added value: +{
+  "anyOf": [
+    {
+      "maximum": 100,
+      "minimum": 0,
+      "type": "number"
+    },
+    {
+      "type": "null"
+    }
+  ],
+  "default": null,
+  "title": "Kernel Context Self Percent"
+}

addedOutput schema / $defs / EvidenceQuality / properties / kernel_context_self_weight

Added value: +{
+  "anyOf": [
+    {
+      "minimum": 0,
+      "type": "integer"
+    },
+    {
+      "type": "null"
+    }
+  ],
+  "default": null,
+  "title": "Kernel Context Self Weight"
+}

addedOutput schema / $defs / EvidenceQuality / properties / unknown_context_self_percent

Added value: +{
+  "anyOf": [
+    {
+      "maximum": 100,
+      "minimum": 0,
+      "type": "number"
+    },
+    {
+      "type": "null"
+    }
+  ],
+  "default": null,
+  "title": "Unknown Context Self Percent"
+}

addedOutput schema / $defs / EvidenceQuality / properties / unknown_context_self_weight

Added value: +{
+  "anyOf": [
+    {
+      "minimum": 0,
+      "type": "integer"
+    },
+    {
+      "type": "null"
+    }
+  ],
+  "default": null,
+  "title": "Unknown Context Self Weight"
+}

addedOutput schema / $defs / EvidenceQuality / properties / unresolved_kernel_self_percent

Added value: +{
+  "anyOf": [
+    {
+      "maximum": 100,
+      "minimum": 0,
+      "type": "number"
+    },
+    {
+      "type": "null"
+    }
+  ],
+  "default": null,
+  "title": "Unresolved Kernel Self Percent"
+}

addedOutput schema / $defs / EvidenceQuality / properties / unresolved_kernel_self_weight

Added value: +{
+  "anyOf": [
+    {
+      "minimum": 0,
+      "type": "integer"
+    },
+    {
+      "type": "null"
+    }
+  ],
+  "default": null,
+  "title": "Unresolved Kernel Self Weight"
+}

addedOutput schema / $defs / EvidenceQuality / properties / unresolved_unknown_context_self_percent

Added value: +{
+  "anyOf": [
+    {
+      "maximum": 100,
+      "minimum": 0,
+      "type": "number"
+    },
+    {
+      "type": "null"
+    }
+  ],
+  "default": null,
+  "title": "Unresolved Unknown Context Self Percent"
+}

addedOutput schema / $defs / EvidenceQuality / properties / unresolved_unknown_context_self_weight

Added value: +{
+  "anyOf": [
+    {
+      "minimum": 0,
+      "type": "integer"
+    },
+    {
+      "type": "null"
+    }
+  ],
+  "default": null,
+  "title": "Unresolved Unknown Context Self Weight"
+}

addedOutput schema / $defs / EvidenceQuality / properties / unresolved_user_self_percent

Added value: +{
+  "anyOf": [
+    {
+      "maximum": 100,
+      "minimum": 0,
+      "type": "number"
+    },
+    {
+      "type": "null"
+    }
+  ],
+  "default": null,
+  "title": "Unresolved User Self Percent"
+}

addedOutput schema / $defs / EvidenceQuality / properties / unresolved_user_self_weight

Added value: +{
+  "anyOf": [
+    {
+      "minimum": 0,
+      "type": "integer"
+    },
+    {
+      "type": "null"
+    }
+  ],
+  "default": null,
+  "title": "Unresolved User Self Weight"
+}

addedOutput schema / $defs / EvidenceQuality / properties / user_context_self_percent

Added value: +{
+  "anyOf": [
+    {
+      "maximum": 100,
+      "minimum": 0,
+      "type": "number"
+    },
+    {
+      "type": "null"
+    }
+  ],
+  "default": null,
+  "title": "User Context Self Percent"
+}

addedOutput schema / $defs / EvidenceQuality / properties / user_context_self_weight

Added value: +{
+  "anyOf": [
+    {
+      "minimum": 0,
+      "type": "integer"
+    },
+    {
+      "type": "null"
+    }
+  ],
+  "default": null,
+  "title": "User Context Self Weight"
+}

Changed7 schema fields changedv0.3.0Aug 21, 2026

addedOutput schema / $defs / CallPathFrame / properties / normalization_merged

Added value: +{
+  "default": false,
+  "title": "Normalization Merged",
+  "type": "boolean"
+}

addedOutput schema / $defs / CallPathFrame / properties / symbol_variant_count

Added value: +{
+  "description": "Exact raw-symbol variant count when symbol_variants_truncated is false; otherwise a conservative observed lower bound",
+  "minimum": 1,
+  "title": "Symbol Variant Count",
+  "type": "integer"
+}

addedOutput schema / $defs / CallPathFrame / properties / symbol_variants_truncated

Added value: +{
+  "default": false,
+  "title": "Symbol Variants Truncated",
+  "type": "boolean"
+}

changedOutput schema / $defs / CallPathFrame / required

Previous value: -[
-  "symbol",
-  "dso"
-]New value: +[
+  "symbol",
+  "dso",
+  "symbol_variant_count"
+]

addedOutput schema / $defs / EvidenceQuality

Added value: +{
+  "additionalProperties": false,
+  "properties": {
+    "actual_event_source": {
+      "default": "unknown",
+      "enum": [
+        "hardware",
+        "software",
+        "unknown"
+      ],
+      "title": "Actual Event Source",
+      "type": "string"
+    },
+    "address_annotation_line_count": {
+      "minimum": 0,
+      "title": "Address Annotation Line Count",
+      "type": "integer"
+    },
+    "aggregated_frame_occurrence_count": {
+      "minimum": 0,
+      "title": "Aggregated Frame Occurrence Count",
+      "type": "integer"
+    },
+    "allowed_conclusions": {
+      "default": [],
+      "items": {
+        "type": "string"
+      },
+      "title": "Allowed Conclusions",
+      "type": "array"
+    },
+    "call_graph_weight": {
+      "minimum": 0,
+      "title": "Call Graph Weight",
+      "type": "integer"
+    },
+    "call_graph_weight_percent": {
+      "maximum": 100,
+      "minimum": 0,
+      "title": "Call Graph Weight Percent",
+      "type": "number"
+    },
+    "collection_limitations": {
+      "default": [],
+      "items": {
+        "type": "string"
+      },
+      "title": "Collection Limitations",
+      "type": "array"
+    },
+    "duplicate_frame_line_count": {
+      "minimum": 0,
+      "title": "Duplicate Frame Line Count",
+      "type": "integer"
+    },
+    "event": {
+      "title": "Event",
+      "type": "string"
+    },
+    "exported_call_path_count": {
+      "minimum": 0,
+      "title": "Exported Call Path Count",
+      "type": "integer"
+    },
+    "exported_hotspot_count": {
+      "minimum": 0,
+      "title": "Exported Hotspot Count",
+      "type": "integer"
+    },
+    "fallback_reason": {
+      "anyOf": [
+        {
+          "type": "string"
+        },
+        {
+          "type": "null"
+        }
+      ],
+      "default": null,
+      "title": "Fallback Reason"
+    },
+    "fallback_used": {
+      "anyOf": [
+        {
+          "type": "boolean"
+        },
+        {
+          "type": "null"
+        }
+      ],
+      "default": null,
+      "title": "Fallback Used"
+    },
+    "forbidden_conclusions": {
+      "default": [],
+      "items": {
+        "type": "string"
+      },
+      "title": "Forbidden Conclusions",
+      "type": "array"
+    },
+    "frame_line_count": {
+      "minimum": 0,
+      "title": "Frame Line Count",
+      "type": "integer"
+    },
+    "inline_frame_count": {
+      "minimum": 0,
+      "title": "Inline Frame Count",
+      "type": "integer"
+    },
+    "input_bytes": {
+      "minimum": 0,
+      "title": "Input Bytes",
+      "type": "integer"
+    },
+    "input_sha256": {
+      "pattern": "^[a-f0-9]{64}$",
+      "title": "Input Sha256",
+      "type": "string"
+    },
+    "limitations": {
+      "default": [],
+      "items": {
+        "type": "string"
+      },
+      "title": "Limitations",
+      "type": "array"
+    },
+    "malformed_record_count": {
+      "minimum": 0,
+      "title": "Malformed Record Count",
+      "type": "integer"
+    },
+    "normalization_merge_count": {
+      "minimum": 0,
+      "title": "Normalization Merge Count",
+      "type": "integer"
+    },
+    "omitted_call_path_weight": {
+      "minimum": 0,
+      "title": "Omitted Call Path Weight",
+      "type": "integer"
+    },
+    "omitted_hotspot_self_weight": {
+      "minimum": 0,
+      "title": "Omitted Hotspot Self Weight",
+      "type": "integer"
+    },
+    "parser_invariants_passed": {
+      "title": "Parser Invariants Passed",
+      "type": "boolean"
+    },
+    "quality_status": {
+      "enum": [
+        "verified",
+        "partial"
+      ],
+      "title": "Quality Status",
+      "type": "string"
+    },
+    "sample_count": {
+      "minimum": 0,
+      "title": "Sample Count",
+      "type": "integer"
+    },
+    "schema_version": {
+      "const": "1.0",
+      "default": "1.0",
+      "title": "Schema Version",
+      "type": "string"
+    },
+    "source_annotation_line_count": {
+      "minimum": 0,
+      "title": "Source Annotation Line Count",
+      "type": "integer"
+    },
+    "source_collection_artifact_sha256": {
+      "anyOf": [
+        {
+          "pattern": "^[a-f0-9]{64}$",
+          "type": "string"
+        },
+        {
+          "type": "null"
+        }
+      ],
+      "default": null,
+      "title": "Source Collection Artifact Sha256"
+    },
+    "source_collection_id": {
+      "anyOf": [
+        {
+          "type": "string"
+        },
+        {
+          "type": "null"
+        }
+      ],
+      "default": null,
+      "title": "Source Collection Id"
+    },
+    "source_line_frame_count": {
+      "minimum": 0,
+      "title": "Source Line Frame Count",
+      "type": "integer"
+    },
+    "source_line_self_percent": {
+      "maximum": 100,
+      "minimum": 0,
+      "title": "Source Line Self Percent",
+      "type": "number"
+    },
+    "source_line_self_weight": {
+      "minimum": 0,
+      "title": "Source Line Self Weight",
+      "type": "integer"
+    },
+    "source_locations_truncated_hotspot_count": {
+      "minimum": 0,
+      "title": "Source Locations Truncated Hotspot Count",
+      "type": "integer"
+    },
+    "total_call_path_count": {
+      "minimum": 0,
+      "title": "Total Call Path Count",
+      "type": "integer"
+    },
+    "total_hotspot_count": {
+      "minimum": 0,
+      "title": "Total Hotspot Count",
+      "type": "integer"
+    },
+    "total_weight": {
+      "minimum": 0,
+      "title": "Total Weight",
+      "type": "integer"
+    },
+    "unicode_replacement_count": {
+      "minimum": 0,
+      "title": "Unicode Replacement Count",
+      "type": "integer"
+    },
+    "unresolved_self_percent": {
+      "maximum": 100,
+      "minimum": 0,
+      "title": "Unresolved Self Percent",
+      "type": "number"
+    },
+    "unresolved_self_weight": {
+      "minimum": 0,
+      "title": "Unresolved Self Weight",
+      "type": "integer"
+    },
+    "warning_count": {
+      "minimum": 0,
+      "title": "Warning Count",
+      "type": "integer"
+    },
+    "warnings_truncated": {
+      "title": "Warnings Truncated",
+      "type": "boolean"
+    },
+    "weight_source": {
+      "title": "Weight Source",
+      "type": "string"
+    },
+    "weight_unit": {
+      "title": "Weight Unit",
+      "type": "string"
+    }
+  },
+  "required": [
+    "quality_status",
+    "parser_invariants_passed",
+    "input_sha256",
+    "input_bytes",
+    "sample_count",
+    "total_weight",
+    "event",
+    "weight_unit",
+    "weight_source",
+    "malformed_record_count",
+    "warning_count",
+    "warnings_truncated",
+    "unicode_replacement_count",
+    "frame_line_count",
+    "duplicate_frame_line_count",
+    "address_annotation_line_count",
+    "source_annotation_line_count",
+    "aggregated_frame_occurrence_count",
+    "unresolved_self_weight",
+    "unresolved_self_percent",
+    "call_graph_weight",
+    "call_graph_weight_percent",
+    "source_line_frame_count",
+    "source_line_self_weight",
+    "source_line_self_percent",
+    "inline_frame_count",
+    "normalization_merge_count",
+    "source_locations_truncated_hotspot_count",
+    "total_hotspot_count",
+    "exported_hotspot_count",
+    "omitted_hotspot_self_weight",
+    "total_call_path_count",
+    "exported_call_path_count",
+    "omitted_call_path_weight"
+  ],
+  "title": "EvidenceQuality",
+  "type": "object"
+}

addedOutput schema / properties / evidence_quality

Added value: +{
+  "$ref": "#/$defs/EvidenceQuality"
+}

changedOutput schema / required

Previous value: -[
-  "analysis_id",
-  "symbol",
-  "items",
-  "total_items"
-]New value: +[
+  "analysis_id",
+  "evidence_quality",
+  "symbol",
+  "items",
+  "total_items"
+]

First observedv0.1.0Aug 1, 2026

TDQS

B3/5.0

Behavior3/5

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint false, covering safety. The description adds behavioral context that results are page-limited and can be filtered by symbol, which goes beyond annotations. However, it does not disclose ordering, the meaning of 'dominant', or pagination cursor behavior; this is acceptable given the annotations but not rich.

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?

The description is a single sentence that is front-loaded and free of filler. Every phrase earns its place, though it is minimal and leaves several details to the schema.

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?

With an output schema and annotations present, return values and safety are covered. The description is adequate for a simple read-only paginated query: it names the resource, mentions pagination, and the optional symbol filter. However, it lacks pagination/cursor semantics, ordering details, and usage routing among siblings, leaving moderate gaps.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters2/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0%, so the description must compensate. It mentions the symbol filter and the notion of a bounded page, but does not explain cursor mechanics, limit defaults, or that analysis_id is a required identifier. This leaves the agent with only the raw schema names and defaults for parameter understanding.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific verb ('Return'), a specific resource ('bounded page of dominant call paths'), and an optional filter ('containing a symbol'). It clearly identifies what the tool does and distinguishes it as a paginated call-path query. It does not explicitly differentiate from siblings like get_hotspot_details, but the resource is specific enough.

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

Usage Guidelines2/5

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

There is no guidance on when to use this tool versus siblings such as get_hotspot_details, analyze_trace_evidence, or list_hotspots. The description implies pagination with 'bounded page' but does not explain typical usage flow, prerequisites, or when the symbol filter is appropriate.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Deploy Server