headersEcho caller's headers.
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
| Name | Required | Description | Default |
|---|---|---|---|
| body | Yes | Response body | |
| status | Yes | HTTP status code | |
| content_type | Yes | Content-Type header |
Changes observed during successful MCP inspections.
Output schema / properties / body / typePrevious value: -"object"New value: +[
+ "object",
+ "string"
+]Input schema / examplesAdded value: +[
+ {}
+]Output schema / (root)Previous value: -nullNew value: +{
+ "properties": {
+ "body": {
+ "description": "Response body",
+ "type": "object"
+ },
+ "content_type": {
+ "description": "Content-Type header",
+ "type": "string"
+ },
+ "status": {
+ "description": "HTTP status code",
+ "type": "number"
+ }
+ },
+ "required": [
+ "status",
+ "content_type",
+ "body"
+ ],
+ "type": "object"
+}Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, and destructiveHint false. Description adds 'Echo caller's headers' which is consistent but minimal beyond 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?
Single, front-loaded sentence with no redundancy. Efficient.
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 zero-parameter, simple echo tool with output schema, description is sufficiently complete.
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?
No parameters exist. Schema coverage is 100%. Description does not need to add parameter details.
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?
Description 'Echo caller's headers' provides a specific verb and resource. It clearly distinguishes from sibling tools like get or post.
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 usage guidance provided. Does not indicate when to use this tool over alternatives or prerequisites.
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.