mpp_linkedin_finderFind a person's email address from their LinkedIn profile URL using MPP (Machine Payments Protocol). Pay-per-request, no API key required.
| Name | Required | Description | Default |
|---|---|---|---|
| url | Yes | The LinkedIn profile URL |
| Name | Required | Description | Default |
|---|---|---|---|
| data | Yes |
Changes observed during successful MCP inspections.
Output schema / (root)Previous value: -nullNew value: +{
+ "$schema": "http://json-schema.org/draft-07/schema#",
+ "additionalProperties": false,
+ "properties": {
+ "data": {}
+ },
+ "required": [
+ "data"
+ ],
+ "type": "object"
+}Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already cover readOnlyHint and openWorldHint, so the bar is lower. The description adds genuinely new behavioral information: the operation incurs a per-request cost and requires no API key. There is no contradiction with the 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?
A single dense sentence front-loads the action and resource, expands the MPP acronym, and conveys cost/auth context. Every phrase adds value with no filler.
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?
For a one-parameter lookup with an output schema and readOnly/openWorld annotations, the description fully covers the action, input, payment model, and authentication requirement. Nothing essential for invoking the tool correctly is missing.
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?
Schema description coverage is 100% and the only parameter, url, is already described as 'The LinkedIn profile URL.' The description merely repeats that notion in prose and adds no format validation, examples, or additional parameter nuance.
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 states a specific verb and resource ('Find a person's email address from their LinkedIn profile URL') plus the distinct delivery mechanism ('using MPP'), which separates it from the sibling linkedin_finder and other enrichment tools. The action and input are unambiguous.
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 provides clear, decision-relevant context: 'Pay-per-request, no API key required.' This tells an agent when the MPP variant is appropriate, though it stops short of explicitly naming when not to use it or which sibling to prefer instead.
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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