Return the JSON-Schema input contract for a tool by name.
| Name | Required | Description | Default |
|---|---|---|---|
| name | Yes | Exact tool name to describe (e.g. "accounting-invoices-create"), as returned by list_tools. |
Changes observed during successful MCP inspections.
Input schema / $schemaRemoved value: -"http://json-schema.org/draft-07/schema#"Input schema / properties / name / descriptionAdded value: +"Exact tool name to describe (e.g. \"accounting-invoices-create\"), as returned by list_tools."Input schema / properties / nameAdded value: +{
+ "type": "string"
+}Input schema / properties / tool_namesRemoved value: -{
- "description": "The names of the tools to describe",
- "items": {
- "type": "string"
- },
- "type": "array"
-}Input schema / requiredPrevious value: -[
- "tool_names"
-]New value: +[
+ "name"
+]Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and idempotentHint=true, indicating this is a safe read operation. The description adds little behavioral context beyond the purpose itself; it does not mention error cases (e.g., unknown tool name) or the exact format of the returned schema. No contradiction 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.
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is a single, focused sentence stating the exact operation. No filler or repetition; every word contributes to the meaning.
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 simple one-parameter introspection tool with strong annotations, the description sufficiently covers its return value. However, it lacks any note about behavior when the tool name is invalid, which might be useful but is not critical given the tool's simplicity.
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 100% with a descriptive parameter entry for 'name' including an example and source ('as returned by list_tools'). The description itself adds no parameter-specific meaning, so it relies on the schema, which is adequate.
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 clearly states a specific verb 'Return' and a well-defined resource: 'the JSON-Schema input contract for a tool by name.' This is unambiguous and distinguishes it from siblings like execute_tool or list_tools.
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?
No guidance is provided on when to use this tool versus alternatives. Siblings are listed but not compared, and there is no mention of prerequisites or typical workflows (e.g., 'use before calling execute_tool'). The implied use case is not stated.
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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