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

Beyond the annotations (idempotent, non-destructive), the description adds the meaningful invariant that an account holds at most one category and explains the 'none' clearing behavior. It could have explicitly stated that assigning a new category replaces the existing one, but the constraint largely conveys this.

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 tight sentences front-load the action and resource, then add the clearing mode and the category lookup reference. There is no filler or repetition.

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 simple setter with full schema coverage and no output schema, the description supplies the core domain context: target accounts, category source, single-category invariant, and clearing option. It leaves the sibling distinction and replace-vs-overwrite semantics implicit, which are the only noticeable gaps.

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 100%, so the account, category, and platform parameters are already documented. The description mostly restates the 'none' behavior from the schema, adding only the My Accounts context rather than new parameter-level meaning.

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 names a specific action ('Assign a category') and resource ('org's own connected accounts (My Accounts)'), and adds the clearing behavior with 'none'. It does not explicitly contrast with the sibling set_account_category, so it falls just short of full sibling differentiation.

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?

The description makes clear the target scope (My Accounts) and points to list_my_account_categories as the source of valid categories, which gives context for use. It does not specify when not to use this tool or compare it to set_account_category, so the guidance is only implicit.

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