scholar-mcp

Find Bridge Papers

find_bridge_papers

Read-only

Find a minimum-hop citation path between two papers by searching citations and references, then poll the returned job handle for the result.

Instructions

Find the shortest citation path between two papers.

Uses BFS over the citation/reference graph. Leverages cached citation and reference lists to minimise API calls.

The search walks outward one rate-limited request per node, so it commonly runs long and returns a job handle to poll with get_job_result rather than the path itself.

A failed upstream request does not abort the search. When one happens, partial is true, failed_requests counts them, and a warning key explains what went unfetched. A partial {"found": false} is not evidence that no path exists, and a partial {"found": true} path is not guaranteed to be the shortest one.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`direction`	No	Expand via citations, references, or both.	both
`max_depth`	No	Maximum hops to search (default 4).
`source_id`	Yes	Starting paper S2 ID.
`target_id`	Yes	Target paper S2 ID.

Output Schema

TableJSON Schema

Name	Required	Description	Default
No arguments

Schema Changelog

Changes observed during successful MCP inspections.

Changed4 schema fields changedv1.10.0Sep 8, 2026
- addedOutput schema / additionalProperties
```
Added value: +true
```
- removedOutput schema / properties
```
Removed value: -{
-  "result": {
-    "type": "string"
-  }
-}
```
- removedOutput schema / required
```
Removed value: -[
-  "result"
-]
```
- removedOutput schema / x-fastmcp-wrap-result
```
Removed value: -true
```
First observedv1.9.0Aug 10, 2026

TDQS

A4.1/5.0

Behavior5/5

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

Goes well beyond the read-only/open-world annotations by disclosing async execution (rate-limited, one request per node, commonly long-running), the job-handle return contract, and detailed partial-failure semantics including that a partial found:false is not proof of no path and a partial found:true is not guaranteed shortest. This is exactly the kind of behavioral context an agent cannot infer from the schema or annotations.

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?

Front-loads the core purpose, then layers algorithm, execution model, and failure semantics in short paragraphs that each carry distinct information. Slightly long, but no sentence is redundant.

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?

Covers everything needed to invoke and interpret the tool: what it computes, that it is asynchronous, how to retrieve the result, and how to read imperfect outcomes. With an output schema present, return-value detail is not required, yet the key job-handle behavior is still explained.

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 schema already documents direction, max_depth, source_id, and target_id. The description adds only indirect meaning (one request per node relates to max_depth), leaving the baseline of 3 appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

States a precise verb and resource ('Find the shortest citation path between two papers') and pins down the algorithm as BFS over the citation/reference graph. This is clearly distinct from single-hop siblings like get_citations/get_references, but it never explicitly contrasts itself with get_citation_graph, which an agent might otherwise confuse as the closer analogue.

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?

Gives strong operational guidance: the call returns a job handle to poll via get_job_result rather than the path, and it explains how to read partial results (partial flag, failed_requests, warning). It stops short of stating when to prefer this over get_citation_graph or other path/graph tools, so there are no explicit alternatives or exclusions.

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