Skip to main content
Glama
thenavidm

substack-mcp

by thenavidm
OverviewSchemaSourceRelated ServersDiscussionsAdmin
TypeScript
Hybrid

Read an analytics report

get_analytics
Read-onlyIdempotent

Read Substack publication analytics reports to track subscriber growth, retention, unsubscribes, referrals, and audience overlap by date range.

Instructions

Read one of the publication-level reports behind the dashboard's Stats tabs.

Reports:

  • unsubscribes: Unsubscribes in a window, broken down by the reason given.

  • unsubscribes_timeseries: Unsubscribes over time.

  • retention: Cohort retention: how much of each signup cohort is still subscribed months later.

  • retention_summary: Headline retention rates at 1, 6 and 12 months.

  • referrals_leaderboard: Which subscribers have referred the most readers.

  • referrals_summary: Gifts sent, accepted and converted.

  • audience_overlap: Other Substacks whose audience overlaps yours, with the overlap percentage. The publications worth collaborating with.

  • audience_locations: How many distinct countries and US states your subscribers span.

  • subscriber_notes: Recent Notes written by your subscribers.

  • paid_subscriber_growth: Paid growth for the period, with new subscriptions and expirations.

  • arr_timeseries: Annual recurring revenue over time.

  • followers_timeseries: Follower count over time.

  • subscribers_timeseries: Subscriber count over time.

  • growth_sources: Where new subscribers came from in a window, ranked by how many each source brought.

  • growth_events: The individual growth events in a window.

  • network_attribution: What share of your subscribers arrived through the Substack network rather than your own channels.

Reports covering a period default to the last 30 days, or the last year for retention.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
limitNoRow cap, for the reports that take one.
reportYesWhich report to read.
to_dateNoEnd of the window, YYYY-MM-DD.
from_dateNoStart of the window, YYYY-MM-DD. Only used by reports covering a period.
publicationNoWhich connected publication to act on, matched loosely against its hostname (for example 'example.substack.com' or just 'example'). Defaults to the first connected publication.

Schema Changelog

Changes observed during successful MCP inspections.

  1. Changed2 schema fields changedv3.0.1
    • removedInput schema / $schema
      Removed value: -"http://json-schema.org/draft-07/schema#"
    • removedInput schema / additionalProperties
      Removed value: -false
  2. First observedv2.1.1

TDQS

A3.8/5.0
Behavior4/5

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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, destructiveHint=false), so the bar is lower. The description still adds real behavioral context beyond structured data: reports covering a period default to the last 30 days, retention defaults to the last year, and limit only applies to 'the reports that take one'.

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 a single framing sentence and a clean bulleted report list where each line earns its place by giving meaning the enum strings lack. The default-window note sits at the very end where it is easy to miss rather than being surfaced with the date parameters.

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?

With no output schema and 16 report variants, the description carries the burden of describing what comes back, and does so moderately well via the per-report lines plus default date behavior. It stops short of describing response shape (rows vs. timeseries payloads) or pagination beyond the limit cap.

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 100%, so the baseline is 3, but the description goes beyond the schema's bare 'Which report to read' by explaining what each of the 16 enum values actually returns, which is exactly the semantic detail needed to pick the right value. The date-window semantics are also elaborated with defaults.

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 names a specific verb and resource ('Read one of the publication-level reports behind the dashboard's Stats tabs') and enumerates all 16 report values with a one-line explanation of each, so the scope is unmistakable. It does not, however, differentiate itself from siblings such as get_growth_sources, get_dashboard_summary or get_revenue_summary, and the 'growth_sources' report value in particular overlaps with a sibling tool name without any disambiguation.

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

Usage Guidelines3/5

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

The phrase 'reports behind the dashboard's Stats tabs' implies when this tool is the right entry point, and the closing sentence supplies default windows. But there is no explicit statement of when to prefer this over get_dashboard_summary, get_email_stats or get_growth_sources, leaving the agent to infer the boundary.

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

Deploy Server

Other Tools