Skip to main content
Glama
thenavidm

substack-mcp

by thenavidm
OverviewSchemaSourceRelated ServersDiscussionsAdmin
TypeScript
Hybrid

Get public info about a publication

get_publication_info
Read-onlyIdempotent

Read a Substack publication's public details—name, description, author, and cover image—from its homepage without authentication, even for publications you don't manage.

Instructions

Read the public details of any Substack publication from its homepage: name, description, author and cover image. Needs no authentication and works on publications you have no relationship with.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
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.
publication_urlNoWhich publication, for example 'example.substack.com'. Defaults to your own.

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

A4.2/5.0
Behavior4/5

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

Annotations already cover readOnly, idempotent and openWorld, but the description adds genuinely new behavioral facts: no authentication is required and it functions on publications with no ownership relationship. It does not mention failure modes or return format, but the added auth/scope context is real value beyond the annotations.

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?

Two tight sentences with zero filler; the scope and the returned fields are front-loaded, and the auth/relationship caveat follows economically.

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?

No output schema exists, but the description enumerates the primary return fields and the auth requirement, which is enough for an agent to call a simple read tool confidently. Minor gaps around the exact response shape and default-parameter behavior remain.

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 both parameters are already documented in the schema. The description adds no parameter-level detail (no mention of hostname matching or the default-to-first-publication behavior), so baseline 3 is appropriate.

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 ('Read') and resource ('public details of any Substack publication from its homepage') and enumerates the returned fields (name, description, author, cover image). The 'public' qualifier and 'any publication' scope cleanly separate it from get_publication_settings, which acts on the agent's own publication.

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?

'works on publications you have no relationship with' gives clear context for when this tool applies, and it implicitly contrasts with own-publication tools. It stops short of explicitly naming the alternative (get_publication_settings) or when to prefer search_publications for discovery.

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