selfhosted-sentry-mcp

list_breadcrumbs

Read-onlyIdempotent

Extract breadcrumbs from a Sentry event to trace the sequence of actions and events leading up to an error.

Instructions

Extract all breadcrumbs from an event, showing the trail of events leading up to an error.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "project_slug": "<project_slug>",
      "event_id": "<event_id>"
    },
    "name": "list_breadcrumbs"
  }
}

Input Schema

Name	Required	Description
`type`	No	Filter by breadcrumb type (e.g., "default", "http", "navigation", "error").
`limit`	No	Max breadcrumbs to return (1-100, default: 50).
`event_id`	Yes	Event ID.
`project_slug`	Yes	Project slug.

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.2.0Jul 12, 2026

TDQS

B3.2/5.0

Behavior3/5

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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, openWorldHint=true, covering the safety profile. The description adds conceptual context (breadcrumbs = trail of preceding events) but omits pagination/return behavior. Minor internal tension: it says 'all breadcrumbs' while the schema caps results via limit (default 50, max 100).

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?

Single front-loaded sentence with no filler. It is appropriately sized, though slightly terse for a tool with a filtering parameter and pagination limit.

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 simple read-only list tool with full schema coverage and annotations handling safety, the description is adequate. It omits any mention of the result limit/pagination and how breadcrumbs are ordered, which an agent might need when interpreting truncated results.

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

Parameters3/5

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

Schema description coverage is 100%, so the schema already documents type, limit, event_id, and project_slug fully. The description adds nothing parameter-specific, so baseline 3 applies.

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?

States a specific verb ('Extract') and resource ('breadcrumbs from an event') with scope ('trail of events leading up to an error'). Clear enough to distinguish from siblings like get_stack_frames or get_sentry_event_details, though it doesn't explicitly name them.

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?

No explicit when-to-use/when-not or alternatives. The phrase 'leading up to an error' implies investigation context, but there is no guidance on when to pick this over get_stack_frames or get_sentry_event_details for diagnosing an error.

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