Crawlora MCP

substack_publication_posts

Read-only

Fetch one page from a Substack publication's public post archive; sort must be new. Use substack_publication for publication details or substack_post for one known post.

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": {
      "publication": "<publication>"
    },
    "name": "substack_publication_posts"
  }
}

Input Schema

Name	Required	Description
`sort`	No	Archive ordering: new, top, or community. Defaults to new.
`limit`	No	Rows per page, 1-50. Defaults to 12.
`offset`	No	Zero-based row offset.
`search`	No	Optional full-text filter over the publication's own posts. A query with no matches returns an empty list.
`publication`	Yes	Required publication subdomain or custom domain.

Output Schema

Name	Required	Description	Default
`data`	Yes	The tool result payload (shape varies per tool; see each tool's docs resource).

Schema Changelog

Changes observed during successful MCP inspections.

First observedOct 7, 2026

TDQS

A4.4/5.0

Behavior4/5

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

Annotations already cover the safety profile (readOnlyHint, openWorldHint), so the bar is lower, and the description adds real context: results come one page at a time and the sort is constrained. It does not, however, explain pagination termination or what a page contains. Note the 'sort must be new' claim conflicts with the schema, which lists top/community as valid.

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 tightly packed sentences with the core purpose front-loaded and the routing guidance second. No filler.

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?

An output schema exists, so return values need no explanation, and annotations carry the safety profile. The description supplies routing and pagination scope, leaving only the sort/schema mismatch as a small gap.

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 coverage is 100%, so the schema already documents publication, sort, limit, offset and search. The description adds only the sort constraint and nothing about limit/offset/search semantics, so the baseline 3 applies.

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 and resource ('Fetch one page from a Substack publication's public post archive'), including the scoping detail that it is the public archive. It explicitly distinguishes itself from two siblings, so an agent can route without opening any schema.

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

Usage Guidelines5/5

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

Names the alternatives (substack_publication for details, substack_post for one known post) with the condition that selects each. The added 'sort must be new' constraint also tells the agent what call shape is valid.

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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