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

Annotations already declare this is a non-read-only, non-destructive, non-idempotent, closed-world mutation. The description reinforces the confirmation gate, but adds nothing about side effects, whether the group name must be unique, or what happens to accounts already in another group.

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?

Two short sentences, front-loaded with the core action and the side effect, with the crucial confirmation requirement trailing. No wasted words.

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 4-parameter mutation with no output schema, the description is adequate but thin: it says nothing about the return value (e.g. the new group's ID), name-uniqueness behavior, or interplay with the optional idempotencyKey that the schema exposes.

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%, so parameters are already fully documented in structured form. The description only restates that accountIds is optional and that confirmation must be true; it adds no constraint or format detail beyond the schema.

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 ('Create an account group') plus the secondary effect of attaching existing accounts. It is clearly distinguishable from sibling create_account, though it does not explicitly contrast with it.

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?

Implies usage ('optionally assign existing accounts') and gives the confirmation prerequisite, but there is no statement of when to prefer this over create_account or how to handle account ownership prerequisites beyond what the schema says.

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