Open Textbook Finder MCP

Find a cheaper older edition

find_older_edition

Read-only

Find earlier editions of a textbook by title or ISBN, optionally with the course edition year, to identify lower-cost alternatives for your course.

Instructions

Suggest earlier editions of a textbook, which usually cost less used than the newest one. Inputs: query (a title or an ISBN) and two optional values: edition_year, the year of the edition your course asks for, and limit, 1 to 10 suggestions. Without edition_year the newest edition Open Library lists counts as the current one, and an ISBN counts as the current edition when you pass one. Suggestions run from the closest older edition down. Editions only one or two releases back often keep the same chapters, but problem sets get reordered, so check the table of contents against your syllabus. The tool does not know prices. Example prompt: "My course wants the 9th edition of Stewart Calculus. Is there an older edition that would work?"

Input Schema

Name	Required	Description
`limit`	No	How many results to return, 1 to 10. Defaults to 5.
`query`	Yes	The textbook title or its ISBN.
`edition_year`	No	Year of the edition your course requires. Leave it out to treat the newest edition found as the current one.

Output Schema

Name	Required	Description
`work_title`	Yes	Title of the book the editions belong to.
`newest_year`	No	Year of the newest edition Open Library lists.
`suggestions`	Yes	Older editions, closest to the current one first.
`current_year`	No	Year of the edition the suggestions are older than.

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Oct 27, 2026

TDQS

A4.1/5.0

Behavior4/5

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

The annotations already establish that this is a read-only, open-world lookup. The description adds useful behavioral context: it does not know prices, suggestions are ordered from the closest older edition downward, and results should be checked against the syllabus.

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 front-loaded with the purpose and generally well organized. It is slightly verbose for a three-parameter tool because it repeats schema details such as the 1-to-10 limit and includes a full example prompt.

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?

Given the simple parameter set, complete schema descriptions, annotations, and an output schema, the description covers the important usage context and limitations. An agent has enough information to call the tool correctly and interpret the caveat about edition contents.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters4/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is complete, so the baseline is 3. The description adds meaning beyond the schema by explaining that query can be a title or ISBN, that edition_year represents the course-required edition year, and that omitting it treats the newest listed edition as current.

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?

The description states a specific verb and resource: suggesting earlier editions of a textbook. It is clear what the tool does, but it does not explicitly distinguish itself from sibling tools such as find_free_textbook or lookup_isbn.

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 example prompt and the course-edition scenario make the intended use case clear. However, it does not explicitly say when to use this instead of the sibling tools or when not to use it.

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

Deploy Server