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

Annotations already declare readOnly, idempotent, closed-world and non-destructive, so the safety profile is covered. The description adds that the value is computed server-side from live Fortnox data spanning all pages, which is useful, but says nothing about latency, aggregation rules, or what happens when only one company exists.

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?

Three short sentences: the definition is front-loaded, the example question follows, and the data-source note is last. Little waste, though the API URL is marginal for an agent that cannot browse it.

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 values need not be described, and the description covers scope, elimination logic, data source and pagination. Only the multi-company precondition and behavior when no group exists are missing.

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% with a single optional 'date' (ÅÅÅÅ-MM-DD to select fiscal year) documented in the schema itself. The description adds no further meaning about the date parameter or its default behavior, so baseline 3 applies.

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 concrete operation: group companies summed with internal invoices eliminated and reported, plus an example question that pins down the intent. It implicitly distinguishes itself from plain balance-sheet/result siblings via the intercompany elimination, though it never names 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?

The example question ('Hur ser koncernen ut sammanlagt, utan handeln mellan bolagen?') gives an implied trigger, but there is no explicit when-to-use vs. get_balance_sheet, get_profit_and_loss or get_key_figures, and no stated preconditions such as requiring multiple connected companies.

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