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

The readOnlyHint annotation already covers the safety profile, so the bar is lower. The description does add real value by disclosing the revenue formula (advance fees included, tax/discounts deducted), but says nothing about return granularity, time zone, or pagination behavior for a multi-month window.

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 tight sentences with the metric definition front-loaded and the API route appended. Nothing is wasted or repeated from the title.

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 read-only analytics endpoint with a fully described schema and no output schema, the description supplies the key missing piece, what the number means, and is nearly complete. Minor gaps remain on return shape and default time window, but an agent can call this correctly.

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 months, currency, and external_customer_id are each documented in the schema, which is the baseline expectation. The description adds no syntax, default, or interaction detail beyond the schema.

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?

Names a specific metric (gross revenue) and defines exactly what it comprises: finalized invoice payments plus advance fees, net of tax and discounts, plus the underlying API route. This clearly separates it from the sibling lago_analytics_mrr, though it does not explicitly call out that distinction.

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 statement of when to use this versus lago_analytics_mrr or the other analytics/list tools, and no note on prerequisites such as which currency or customer scope must be set. The agent has to infer usage entirely from the metric name.

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