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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=false, and destructiveHint=false, so the safety profile is known. The description adds valuable behavioral context by saying this returns the exact Home dashboard headline figures in one call, but it does not discuss permissions, freshness, or performance characteristics.

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 front-loaded with the core purpose and returned figures, then gives usage examples and sibling routing. Despite being longer than a bare-minimum sentence, every clause helps an agent choose the tool or avoid a wrong sibling.

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?

For a simple read-only snapshot tool with one optional parameter, full schema coverage, and annotations that cover safety, the description is complete. It explains what the tool returns, when to use it, and which alternatives handle adjacent questions.

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?

The single optional company parameter has 100% schema description coverage, including how to obtain company IDs via list_companies and default behavior when omitted. The tool description does not add any further meaning beyond the schema, so the baseline of 3 is appropriate.

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 states a specific verb and resource ('get the headline money figures') and explicitly lists the exact figures returned: cash, open invoices, open bills, and monthly net profit. It clearly distinguishes the tool from siblings like get_profit_and_loss, get_invoices, get_bills, get_aged_debtors, and get_aged_creditors.

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 gives explicit use cases ('how am I doing', 'how much am I owed', 'what do I owe', quick business health check) and names alternatives for adjacent needs: past-month performance goes to get_profit_and_loss, line-level invoice/bill detail goes to get_invoices/get_bills, and ageing goes to get_aged_debtors/get_aged_creditors.

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