Crawlora MCP

substack_user_search

Read-only

Search public Substack writer profiles by name or handle. Each result carries the same subscriber signals as substack_user, so a search enumerates writers without a second lookup per profile. Returns 20 profiles per page; rely on has_more rather than a fixed depth, since result counts vary by query.

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": {
      "query": "<query>"
    },
    "name": "substack_user_search"
  }
}

Input Schema

Name	Required	Description	Default
`page`	No	Zero-based page. 20 profiles per page; depth depends on the query.
`query`	Yes	Required search text matched against profile names and handles.

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 5, 2026

TDQS

A4.1/5.0

Behavior4/5

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

Annotations already declare readOnlyHint and openWorldHint, so safety is covered. The description adds valuable non-schema behavior: page size of 20, variability of depth by query, and the guidance to rely on has_more rather than a fixed depth. No auth or rate-limit info, but strong for a read-only search.

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?

Three sentences, front-loaded with purpose before the sibling relationship and pagination nuance. Slight overlap with the schema on page size keeps it from being maximally tight, but every sentence earns its place.

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 an output schema present, return values need not be explained, and the description still covers purpose, the sibling equivalence, and pagination behavior. It is complete enough for correct invocation; minor omission of any query-formatting caveats.

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% and both parameters (query, page) are already documented there. The description's '20 profiles per page' largely restates the page parameter description, adding little semantic meaning beyond the schema baseline.

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 ('Search public Substack writer profiles by name or handle') and explicitly distinguishes itself from the substack_user sibling by noting results carry the same subscriber signals. An agent can tell what this does without opening the schema.

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?

The clause 'a search enumerates writers without a second lookup per profile' effectively tells the agent to prefer this over per-profile substack_user calls. It gives clear context but stops short of naming when to use other siblings like substack_search explicitly.

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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