Expense Analysis

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

Annotations already declare readOnly, idempotent, and non-destructive behavior. The description adds that the tool is '[LIMITED]' and returns only category structure, not actual expense data, which is valuable behavioral context beyond the annotations.

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 two sentences: the first clearly states the core purpose and limitation, the second points to the alternative. No fluff, immediately scannable, and appropriately front-loaded.

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?

With no output schema, the description clearly states that the tool returns 'category structure only,' which sets expectations. It also points to the sibling tool for actual data, covering the main functional gap. However, it does not detail what the category structure contains (e.g., totals, counts), so it is not fully complete.

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 parameters are already well-documented. The description does not add specific parameter-level detail beyond what the schema provides, but it reinforces the account_range defaults indirectly via the alternative tool example.

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 clearly states the tool analyzes expenses by account class and explicitly notes it 'Returns category structure only.' This distinguishes it from sibling tools like fortnox_account_activity and fortnox_expense_analysis's limited scope.

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?

It explicitly says when not to use this tool ('For actual expense data, use fortnox_account_activity') and provides a concrete alternative with parameters. This gives the agent clear decision guidance.

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