libofcongress-mcp-server

Search Historical Newspapers

libofcongress_search_newspapers

Read-only

Search historical newspaper pages in the Chronicling America corpus. Returns matching pages with OCR text excerpts (~500 characters), publication title, date, state, and the page URL needed for libofcongress_get_newspaper_page. Filters by keyword, date range, US state, and newspaper title. The OCR excerpts are sufficient for relevance assessment — call libofcongress_get_newspaper_page with the returned url field to read the full page text. OCR quality varies: 19th-century and degraded materials may contain fragmented or garbled text.

Input Schema

TableJSON Schema

Name	Required	Description
`page`	No	1-indexed page number for paginating results.
`limit`	No	Results per page. Default 25, max 100.
`query`	Yes	Keyword search across OCR text and newspaper metadata.
`state`	No	Filter to newspapers published in this US state. Use the full state name, lowercase (e.g., "oklahoma", "new york").
`date_end`	No	End year for date filter, inclusive (e.g., 1920). Omit for no upper bound.
`date_start`	No	Start year for date filter, inclusive (e.g., 1900). Omit for no lower bound.
`newspaper_title`	No	Filter to a specific newspaper by title (partial match accepted).

Output Schema

TableJSON Schema

Name	Required	Description
`page`	No	Current 1-indexed page number.
`error`	No	Present when the call failed. Absent on success.
`items`	No	Newspaper page results matching the search query and filters.
`pages`	No	Total retrievable pages. For result sets larger than LOC will page through (~100,000 pages) this is capped, and a notice discloses how to reach the rest (partition by date/state).
`total`	No	Total number of matching newspaper pages in the result set.
`notice`	No	Recovery hint when results are empty or a page is out of range — echoes applied filters and suggests how to broaden. Absent on successful result pages.
`has_next`	No	True when a retrievable next page follows this one. Never promises a page past LOC's ~100,000-item retrieval ceiling.
`totalCount`	No	Total matching newspaper pages — mirrors output.total for agent reasoning.
`effectiveQuery`	No	The keyword query as submitted to the Chronicling America API, after trimming.

Schema Changelog

Changes observed during successful MCP inspections.

First observedSep 19, 2026

TDQS

A4.3/5.0

Behavior4/5

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

Annotations already indicate read-only and open-world behavior. The description adds valuable behavioral context: excerpt length (~500 characters), the warning about OCR quality in 19th-century/degraded material, and the dependency relationship between this tool's url field and get_newspaper_page. It does not disclose ordering/sorting behavior, but that is likely covered by the output schema.

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?

Three sentences, each earning its place: the first states purpose and returns, the second gives routing guidance, and the third warns about data quality. Information is front-loaded; no filler or repetition.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a 7-parameter tool with a full output schema, the description covers everything an agent needs: what is searched, what is returned, how to proceed to the next step, and data quality caveats. Nothing essential is missing.

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 baseline is 3. The description's summary of filters (keyword, date range, state, title) merely mirrors the schema; it adds no new parameter-specific meaning beyond what the property descriptions already provide.

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?

The description states a specific verb ('Search'), a precise resource ('historical newspaper pages in the Chronicling America corpus'), and concrete return fields (OCR excerpts, title, date, state, URL). It clearly distinguishes this from the broader libofcongress_search and from libofcongress_get_newspaper_page by framing the page URL as the input to that sibling.

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 description gives explicit workflow guidance: OCR excerpts are sufficient for relevance assessment, and the returned url field should be passed to libofcongress_get_newspaper_page for full text. It gives context for when to stop at this tool, but it does not explicitly say when to prefer other siblings like libofcongress_search or search_subjects.

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

All libofcongress-mcp-server tools Inspect

Try in Browser

One endpoint for every MCP toolRayrun runs every MCP server behind one URL and holds the credentials. Each call is decided per client, tool, and argument, then recorded.ray.runAd

Glama MCP Gateway

Add one secure layer between your agents and this server.