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

Annotations already declare it is a non-read-only, non-idempotent, non-destructive creation. The description adds genuinely useful context beyond them by stating the response contains the new category with its ID, but says nothing about duplicate names or whether the created category is immediately usable in records.

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, the operation is stated first and the return behavior second, with zero 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?

An output schema exists so return detail need not be spelled out, and annotations cover the safety profile for this mutation. Only edge-case behavior such as duplicate-name or invalid-color rejection is left unaddressed.

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%, with all four params documented including the INCOME/EXPENSE enum, so the schema carries the semantics. The description only restates the type distinction already in the enum documentation, adding no new syntax or format detail.

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) and resource (category) plus the two subtype modes (income or expense) and the purpose (classifying records). The resource name distinguishes it from siblings like create_record and create_payment_method, though it never explicitly contrasts with them.

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 on when to use this versus update_category or list_categories, and no prerequisites or constraints (e.g. duplicate-name handling). The phrase 'for classifying records' hints at purpose but is not a usage condition.

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