Revenue Breakdown by Segment

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

Annotations only carry readOnlyHint=true, so the description must carry behavioral context and it does: as-reported vs derived distinction, operating margin derived as operating income / revenue for the same folded member QName and period, one table per axis, and an explicit overlap warning against summing rows. This is far beyond what the annotations disclose.

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?

Front-loads the purpose and keeps every clause informative — the overlap warning and derived-margin rule earn their space. It is somewhat dense and run-on (nested em-dash asides in a single paragraph), which slightly hurts scannability, but there is minimal filler.

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?

No output schema exists, so the description must convey the return shape, and it does: one table per axis, a consolidated total row per table, as-reported vs derived fields. For a two-parameter read tool with thin annotations, this is complete enough to call and interpret 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% and both parameters (ticker, maxYears) are fully documented in the schema with examples, format (MIC:TICKER) and defaults/max. The description adds no parameter-level detail beyond the schema, so the baseline of 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 specific verb (Get) and resource (revenue disaggregated by business segment, geography, product/service) plus the extra payload (operating income by segment). It explicitly differentiates from siblings by naming GetFinancialStatement and GetFinancialFact as the route for consolidated figures. An agent can pick this tool apart from the other financial tools without inspecting either schema.

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?

Explicit scope limits: 'Annual fiscal years only', 'latest restated values', plus a clear 'use X instead' for consolidated figures. It also flags the trap case (row overlap, never sum rows) which tells the agent how to interpret results correctly. Both when-to-use and when-not-to-use are present.

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