set_business_account_username

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

The description does not add behavioral context beyond the annotations. It fails to disclose that the 'username' parameter is optional in the schema, which likely means omitting it could clear the username, nor does it mention uniqueness constraints or side effects. The annotations already cover read-only/mutation status, so this adds little value.

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, concise sentence with no fluff or unnecessary wording. It is front-loaded and easy to parse, though it sacrifices content for brevity.

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?

Given the minimal schema (no parameter descriptions), no output schema, and the availability of closely related sibling tools, the description is too sparse. It lacks operational details such as how to obtain the business_connection_id, whether username can be omitted, and how this action fits with other business account settings.

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 description coverage is 0%, and the description does not compensate. It mentions 'username' but does not explain the required 'business_connection_id' parameter, its purpose, or the optional nature of 'username'. The one short sentence provides no meaningful parameter semantics beyond what the parameter names already imply.

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 'Set the username of a business account' uses a specific verb and resource, clearly indicating the operation. It distinguishes itself from sibling 'set_business_account_name' by targeting the username rather than the display name.

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 like set_business_account_name, nor any prerequisites or exclusions. The only implied context is that it is for setting a username, but no direct comparison or decision framework is given.

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