One pin: image, description, outbound link, saves, board and author. (1 credit)
Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.
{
"id": 1,
"jsonrpc": "2.0",
"method": "tools/call",
"params": {
"arguments": {
"url": "<url>"
},
"name": "pinterest_pin"
}
}| Name | Required | Description | Default |
|---|---|---|---|
| url | Yes | Pin URL. |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds genuinely non-structured information — the returned field set and a '(1 credit)' cost signal — which is useful for planning, but it says nothing about failure modes for invalid/private pins or whether the response is partial.
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?
It is short and front-loads the resource, which is good, but the whole description is one unpunctuated fragment and the trailing '(1 credit)' is tacked on rather than integrated. Nothing is wasted, yet the compression costs clarity on the core action.
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?
With no output schema, listing the returned fields is the right compensating move and is the description's main value. Still, for a lookup-by-URL tool it omits the essential framing that the input is a pin URL and what the tool does with it, so an agent must read the schema to reconstruct the operation.
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?
With a single parameter at 100% schema description coverage, the schema already documents 'url' as 'Pin URL.' The description adds no format or syntax detail, but baseline 3 applies when the schema carries the parameter burden and the description implicitly scopes to one pin per URL.
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 names the resource ('One pin') and enumerates what it returns (image, description, outbound link, saves, board, author), which lets an agent distinguish it from pinterest_board. However, it is a noun-phrase fragment with no verb, so it never states that the tool *fetches* a single pin, leaving the operation implied rather than declared.
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?
There is no when-to-use guidance, no prerequisite (e.g. that the URL must be a pin URL rather than a board or profile URL), and no reference to the adjacent pinterest_board sibling that an agent would likely confuse it with. The agent must infer invocation conditions entirely.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.