convert_isbnConvert an ISBN between ISBN-10 and ISBN-13 (recomputing the check digit). ISBN-10 -> ISBN-13 prefixes "978"; ISBN-13 -> ISBN-10 works only for the 978 prefix.
| Name | Required | Description | Default |
|---|---|---|---|
| isbn | Yes | The ISBN to convert. |
Changes observed during successful MCP inspections.
Input schema / examplesAdded value: +[
+ {
+ "isbn": "978-0-306-40615-7"
+ },
+ {
+ "isbn": "0306406152"
+ }
+]Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already indicate readOnly, openWorld, idempotent, and non-destructive. The description adds behavioral context (check digit recomputation, prefix condition) that goes beyond annotations.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
Two sentences, no wasted words, front-loaded with the core action and supported by specific behavioral notes.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the simple single-parameter tool and rich annotations, the description completes the picture with conversion logic and prefix constraint.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
The only parameter 'isbn' is described in schema with type string. The description adds semantic detail about conversion behavior, adding value beyond the schema's coverage.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description precisely states the tool converts between ISBN-10 and ISBN-13 with check digit recomputation, clearly distinguishing it from sibling tools like validate_isbn.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description explains when to use (converting formats) and notes the limitation that ISBN-13 to ISBN-10 only works for the 978 prefix, providing clear context without explicit alternatives.
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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