OpenAPI MCP Gateway

Deletes a pet.

delete_pet

DestructiveIdempotent

Delete a pet from the system using its unique ID. Provide the pet ID to remove the record permanently.

Instructions

Delete a pet.

Tool call template

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": {
      "petId": "<petId>"
    },
    "name": "delete_pet"
  }
}

Input Schema

Name	Required	Description	Default
`petId`	Yes	Pet id to delete
`api_key`	No

Schema Changelog

Changes observed during successful MCP inspections.

Changed7 schema fields changedv0.6.2Aug 11, 2026
- removedInput schema / properties / api_key / anyOf
```
Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]
```
- removedInput schema / properties / api_key / default
```
Removed value: -null
```
- removedInput schema / properties / api_key / title
```
Removed value: -"Api Key"
```
- addedInput schema / properties / api_key / type
```
Added value: +"string"
```
- addedInput schema / properties / petId / format
```
Added value: +"int64"
```
- removedInput schema / properties / petId / title
```
Removed value: -"Petid"
```
- removedInput schema / title
```
Removed value: -"upstream_callableArguments"
```
First observedv1.0.0Jun 11, 2026

TDQS

D1.9/5.0

Behavior2/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

The description adds no behavioral transparency beyond the annotations. The annotations already declare destructiveHint: true and idempotentHint: true, and the description merely confirms deletion. No additional context such as irreversibility, related effects, or auth requirements is provided.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness2/5

Is the description appropriately sized, front-loaded, and free of redundancy?

While the description is extremely short and front-loaded, this is under-specification rather than conciseness. It consists of three words and leaves the user without any actionable detail beyond the tool name.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness2/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a destructive operation with two parameters and no output schema, the description is incomplete. It lacks context about the petId requirement, the api_key parameter, potential side effects, or the return value. The annotation provides some context, but the description itself does not stand on its own.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters1/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The schema includes two parameters: petId (with a short description) and api_key (undocumented). The description 'Delete a pet.' contributes nothing to understanding either parameter. With schema coverage at only 50%, the description was expected to compensate but fails entirely.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose2/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description 'Delete a pet.' is a tautology that simply restates the tool name and title. It identifies the verb and resource but adds no specificity about scope, conditions, or what distinguishes it from sibling delete tools like delete_user or delete_order.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines2/5

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. There is no mention of prerequisites, idempotency implications, or contexts where a different tool (e.g., update_pet) would be more appropriate. The only implication is that you use it to delete a pet, which is already obvious.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.