Librivox

Authors

authors

Read-onlyIdempotent

Search LibriVox authors by last name or keyword; supports pagination via limit/offset. Returns author id, first/last name, and a link to their LibriVox profile.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`limit`	No
`query`	No
`offset`	No
`last_name`	No

Output Schema

TableJSON Schema

Name	Required	Description	Default
`authors`	No	List of authors matching search criteria

Schema Changelog

Changes observed during successful MCP inspections.

Changed11 schema fields changedJun 2, 2026
- removedOutput schema / properties / authors / items / properties / birth_year
```
Removed value: -{
-  "description": "Birth year",
-  "type": [
-    "number",
-    "null"
-  ]
-}
```
- removedOutput schema / properties / authors / items / properties / death_year
```
Removed value: -{
-  "description": "Death year",
-  "type": [
-    "number",
-    "null"
-  ]
-}
```
- removedOutput schema / properties / authors / items / properties / description
```
Removed value: -{
-  "description": "Author biography",
-  "type": "string"
-}
```
- addedOutput schema / properties / authors / items / properties / dob
```
Added value: +{
+  "type": "string"
+}
```
- addedOutput schema / properties / authors / items / properties / dod
```
Added value: +{
+  "type": "string"
+}
```
- addedOutput schema / properties / authors / items / properties / first_name
```
Added value: +{
+  "type": "string"
+}
```
- changedOutput schema / properties / authors / items / properties / id / type
```
Previous value: -"number"New value: +"string"
```
- addedOutput schema / properties / authors / items / properties / last_name
```
Added value: +{
+  "type": "string"
+}
```
- removedOutput schema / properties / authors / items / properties / name
```
Removed value: -{
-  "description": "Author name",
-  "type": "string"
-}
```
- removedOutput schema / properties / authors / items / properties / url_librivox
```
Removed value: -{
-  "description": "LibriVox author page URL",
-  "type": "string"
-}
```
- removedOutput schema / properties / authors / items / properties / url_wikipedia
```
Removed value: -{
-  "description": "Wikipedia URL if available",
-  "type": [
-    "string",
-    "null"
-  ]
-}
```

Changed2 schema fields changedMay 22, 2026

addedInput schema / examples

Added value: +[
+  {
+    "query": "Austen"
+  },
+  {
+    "last_name": "Shakespeare",
+    "limit": 5
+  }
+]

changedOutput schema / (root)

Previous value: -nullNew value: +{
+  "properties": {
+    "authors": {
+      "description": "List of authors matching search criteria",
+      "items": {
+        "properties": {
+          "birth_year": {
+            "description": "Birth year",
+            "type": [
+              "number",
+              "null"
+            ]
+          },
+          "death_year": {
+            "description": "Death year",
+            "type": [
+              "number",
+              "null"
+            ]
+          },
+          "description": {
+            "description": "Author biography",
+            "type": "string"
+          },
+          "id": {
+            "description": "Author ID",
+            "type": "number"
+          },
+          "name": {
+            "description": "Author name",
+            "type": "string"
+          },
+          "url_librivox": {
+            "description": "LibriVox author page URL",
+            "type": "string"
+          },
+          "url_wikipedia": {
+            "description": "Wikipedia URL if available",
+            "type": [
+              "string",
+              "null"
+            ]
+          }
+        },
+        "type": "object"
+      },
+      "type": "array"
+    }
+  },
+  "type": "object"
+}

First observedMay 18, 2026

TDQS

A4/5.0

Behavior3/5

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

Annotations already declare read-only, idempotent, and non-destructive behavior. The description adds pagination support and return format, but does not disclose behavioral caveats such as result limits or open-world completeness. No contradictions with annotations.

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?

Two tightly structured sentences: one for functionality, one for return values. No redundant or extraneous content, and key details are front-loaded.

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

Completeness4/5

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

With annotations and an output schema, the description provides adequate context for invoking the tool. It could add more on parameter ranges or usage scenarios, but it is complete enough for a simple search tool.

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 has zero description coverage, but the description compensates by mapping query and last_name to search criteria and limit/offset to pagination, covering all four parameters. It does not detail constraints or combinations, but provides sufficient meaning.

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?

Description states 'Search LibriVox authors' with specific search criteria (last name, keyword) and returns (id, name, profile link), clearly distinguishing it from sibling tools like audiobooks or tracks.

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?

No explicit when-to-use or alternative guidance is provided. The usage is implied by the clear purpose, but the description does not contrast with other lookup tools or mention exclusions.

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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