Open Graph card fields for a URL.
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": "og"
}
}| Name | Required | Description | Default |
|---|---|---|---|
| url | Yes | Public URL |
Changes observed during successful MCP inspections.
Input schema / properties / urlAdded value: +{
+ "description": "Public URL",
+ "type": "string"
+}Input schema / requiredAdded value: +[
+ "url"
+]Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations exist, so the description carries the full behavioral burden and delivers almost none of it. It does not say whether the tool performs a live network fetch, what happens when the target page has no Open Graph tags, whether errors are raised or empty fields returned, or if any rate limiting applies.
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 a single short fragment with no padding, so nothing is wasted, but the terseness comes at the cost of under-specification rather than disciplined brevity. A verb and a return-shape clause would fit in the same sentence length.
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 annotations and no output schema, the description is the only source of information about results, and it never enumerates which Open Graph fields are returned (title, description, image, type, site_name) or their shape. For a fetch-and-extract tool that is a meaningful gap an agent must guess around.
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?
There is a single required parameter with 100% schema description coverage ('Public URL'), so the schema already does the explanatory work and the baseline of 3 applies. The description adds nothing about URL format, redirect handling, or scheme requirements beyond what the schema states.
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 fragment 'Open Graph card fields for a URL' names the resource but supplies no verb, so it is unclear whether the tool fetches a page and extracts OG tags, or generates card fields from input. The opaque name 'og' only becomes interpretable through this description, and nothing distinguishes it from siblings such as metadata, meta_scrape, or embed.
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 statement of when to use this tool versus metadata, meta_scrape, scrape, link_check, or embed, all of which plausibly overlap. The word 'Public' implies a URL accessibility prerequisite but that is inference, not guidance, and no exclusions are given.
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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