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

Annotations already indicate readOnlyHint=false, and the description simply confirms the create action. It adds only the 'top-level' qualifier, but does not disclose details like whether duplicate names are rejected, whether categories can be deleted, or what the creation response contains.

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?

A single sentence with no filler, and the most important scoping information ('top-level', 'expense or income') is placed upfront. Every word earns its place.

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?

The tool is relatively simple and the schema defines required fields and constraints, so an agent can probably invoke it correctly. However, the description omits any usage context or expected behavior beyond creation, and with an output schema present it could have briefly stated what the created category looks like.

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 only 25%, so the description needs to compensate, but it does not explain the name, icon, or color parameters. It only implicitly maps the 'expense or income' wording to the 'kind' enum, which is a small contribution.

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 ('Creates'), a clear resource ('category'), and a distinguishing scope ('top-level expense or income'). This differentiates it from sibling tools like update_category or delete_category without needing to open schemas.

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 gives no guidance on when to use this tool versus alternatives such as update_category, delete_category, or list_categories. It also does not explain when a top-level category is appropriate or how this relates to other category operations.

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