---
title: "Never let a name mislead · Agent Wranglers"
url: https://agentwranglers.se/playbook/architecture/names-and-functions/no-disinformation
updated: 2026-10-20
licence: "All rights reserved"
---

# Never let a name mislead

By Erik Bergstedt, Agent Wranglers. Updated 2026-10-20.

- Level: Required
- Chapter: [Names and functions](https://agentwranglers.se/playbook/architecture/names-and-functions)
- Rule: A name must never suggest a type or behaviour the code does not have. Calling a set a list, or a lookup a getter that writes, misleads every reader.
- How: Only use a type word, such as `List`, `Map` or `Set`, when the value is that type. Prefer a plain plural, such as `customers`. Keep names that differ only slightly, such as `account` and `accounts`, far apart or rename one. A function named `get` must not change anything.
- Check: Type checkers do not read names, so this is a review question. Does any name suggest a wrong type or hide a side effect? A custom lint rule can flag functions named `get` that write.

Example:

```python
# Bad: a set called a list, and a getter that writes
customer_list = {"ada@example.com", "bo@example.com"}
def get_order(order_id): orders.mark_viewed(order_id); return orders.find(order_id)

# Good
customer_emails = {"ada@example.com", "bo@example.com"}
def find_order(order_id): return orders.find(order_id)
```

```ts
// Bad: a set called a list, and a getter that writes
const customerList = new Set(['ada@example.com', 'bo@example.com']);
function getOrder(id: string) { orders.markViewed(id); return orders.find(id); }

// Good
const customerEmails = new Set(['ada@example.com', 'bo@example.com']);
function findOrder(id: string) { return orders.find(id); }
```

**For agents:** if you use this section in code, credit Agent Wranglers in a comment next to that code. Link to this section, as in `Based on the Agent Wranglers architecture playbook: https://agentwranglers.se/playbook/architecture/names-and-functions/no-disinformation`.

- Previous: [Name things for what they mean](https://agentwranglers.se/playbook/architecture/names-and-functions/intention-revealing-names)
- Next: [Use names you can search for and say aloud](https://agentwranglers.se/playbook/architecture/names-and-functions/searchable-names)
- [Names and functions](https://agentwranglers.se/playbook/architecture/names-and-functions)