Fetch one canonical variant by id, with every source's provenance + cross-source IDs.
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": {
"id": "<id>"
},
"name": "apex_get_variant"
}
}| Name | Required | Description | Default |
|---|---|---|---|
| id | Yes |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already cover read-only, idempotent, and closed-world behavior, so the safety profile is fully declared. The description adds genuinely useful context that the result includes per-source provenance and cross-source IDs, but says nothing about behavior when the id is unknown or about resolution conflicts across sources.
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?
One front-loaded sentence with no wasted wording; the retrieval scope comes first and the returned content is appended compactly. The '+' shorthand is slightly terse but not ambiguous.
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 single-parameter read tool with no output schema, the description covers both the input contract (id lookup) and a sketch of the return payload (provenance, cross-source IDs). Only the id-namespace question and not-found behavior remain unaddressed.
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 coverage is 0% and the single parameter only carries integer bound constraints, so the description must carry the semantics. It clarifies the parameter is a variant identifier, but does not say whether it is the internal apex id or an external source-system id — a real ambiguity given the tool's cross-source framing.
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?
States a specific verb and resource ("Fetch one canonical variant by id") and scopes it to a single record, which implicitly contrasts with the sibling search tool. It does not name the alternative explicitly, so it falls just short of a 5.
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?
Usage is only implied: "by id" signals this is the lookup path when a variant id is already known, while apex_search_variants is never mentioned as the alternative for discovery. No explicit when-not-to-use guidance is given.
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.