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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), and the description adds real context beyond them: the figures are computed server-side from live Fortnox data and aggregated over all result pages, so the agent knows results are fresh and not paginated. It does not describe caching or latency, which keeps it short of a 5.

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 definition is front-loaded with the definition of the report and its time semantics, followed by an illustrative example. The trailing Fortnox API URL and 'over all pages' note are slightly cluttering but each clause still carries information.

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 an output schema present, the description need not explain return values, and it does state the aggregation level (per account group) and the comparison logic. The only gap is the financialyear parameter, which is left entirely to the schema.

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 coverage is 100%, so both parameters are already fully documented in the schema (including the 'omitted = current balances' default and the YYYY-MM-DD format). The description restates the date/comparative behaviour but adds no syntax or formatting detail beyond it, and the financialyear parameter is never mentioned.

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 the concrete resource (balance sheet) and its composition (assets, equity, liabilities broken down per account group), plus the time semantics (now, or a chosen date compared with the same date last year). That is enough to separate it from get_profit_and_loss or get_key_figures without opening the schema, though no sibling is named explicitly.

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 example question ('Vad äger bolaget och vad är det skyldigt?') plus the date/prior-year framing implies when the tool is appropriate, but there is no explicit when-to-use/when-not guidance and no alternatives among the many overlapping reporting siblings (get_group_consolidation, get_year_end_package, get_management_report).

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