xpay Academic Research Collection

search_crossref

Search academic papers from CrossRef database.

CrossRef is a scholarly infrastructure organization that provides 
persistent identifiers (DOIs) for scholarly content and metadata.
It's one of the largest citation databases covering millions of 
academic papers, journals, books, and other scholarly content.

Args:
    query: Search query string (e.g., 'machine learning', 'climate change').
    max_results: Maximum number of papers to return (default: 10, max: 1000).
    **kwargs: Additional search parameters:
        - filter: CrossRef filter string (e.g., 'has-full-text:true,from-pub-date:2020')
        - sort: Sort field ('relevance', 'published', 'updated', 'deposited', etc.)
        - order: Sort order ('asc' or 'desc')
Returns:
    List of paper metadata in dictionary format.
    
Examples:
    # Basic search
    search_crossref("deep learning", 20)
    
    # Search with filters
    search_crossref("climate change", 10, filter="from-pub-date:2020,has-full-text:true")
    
    # Search sorted by publication date
    search_crossref("neural networks", 15, sort="published", order="desc")

Input Schema

TableJSON Schema

Name	Required	Description	Default
`query`	Yes
`kwargs`	Yes
`max_results`	No

Schema Changelog

Changes observed during successful MCP inspections. Dates show when Glama detected each change.

First observedAug 14, 2026

TDQS

B3.3/5.0

Behavior2/5

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

With no annotations, the description carries the full burden, but it fails to disclose a critical inconsistency: it presents `**kwargs` as Python keyword arguments while the input schema declares a single required string property named `kwargs`. The description does not explain how to serialize filter/sort/order into that string, making it unclear how to correctly invoke the tool.

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?

The description is well-structured with Args, Returns, and Examples sections, making it easy to scan. The introductory background on CrossRef is slightly extraneous but not harmful. It earns a high score for organization and front-loading the purpose, though it is longer than strictly necessary.

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

Completeness2/5

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

Despite the detailed examples, the description lacks essential context for correct invocation: the schema requires `kwargs`, but the description treats it as optional Python `**kwargs`; there is no guidance on string formatting. It also omits pagination, error behavior, and the shape of returned metadata (no output schema exists), leaving significant gaps for an agent.

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?

The description adds meaningful semantics for query (with examples), max_results (default and max), and kwargs sub-parameters (filter, sort, order). However, it never bridges the gap between the `**kwargs` concept and the actual `kwargs` string parameter in the schema, so the added value is undermined by the unresolved serialization question.

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 opens with a clear, specific verb+resource statement: 'Search academic papers from CrossRef database.' It explicitly identifies the database and the search action, distinguishing it from sibling tools like search_arxiv or search_pubmed despite not naming alternatives.

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?

Usage is implied by the name and 'Search academic papers from CrossRef database,' but there is no explicit guidance on when to choose this over other search tools (e.g., search_papers, paper-search-advanced) or when not to use it. No alternatives or exclusions are mentioned.

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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TDQS

C2.6/5.0

Disambiguation1/5

Multiple tools appear to serve the same purpose, such as search_arxiv and search-arxiv, or papers-search-basic, paper-search-advanced, search_papers, and search. The download/read tools for different sources follow similar patterns, but some return 'not supported' messages, making it unclear which tools are actually functional.

Naming Consistency1/5

Tool names mix snake_case, kebab-case, and bare verbs without a consistent pattern. For example, about_nanci, analysis-citation-network, download-full-paper-arxiv, fetch, and search_arxiv all coexist, and the same action for different sources alternates conventions (search-arxiv vs search_arxiv).

Tool Count1/5

With 53 tools, the server is heavily over-scoped. Many tools are redundant or near-duplicates, such as six source-specific search tools plus an aggregate search, and the inclusion of both paper and clinical trial tools in one server creates unnecessary bloat.

Completeness3/5

The server covers a wide range of research workflows, including search, download, read, citations, authors, and clinical trials. However, several tools (crossref/pubmed download/read) are non-functional dead ends, and the redundancy makes it harder to navigate the surface.

Resources

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