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

Annotations only declare readOnlyHint=true, so the description carries the behavioral load and does so richly: partial/in-progress fiscal years with period_complete false and never-compare-to-full-year guidance, DATA_UNAVAILABLE refusal for an unreachable store, crosswalk attribution caveat, public-domain source, and free access. This is well beyond what the annotation provides.

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?

Dense but deliberately front-loaded around 'TWO SHAPES', with each sentence carrying operational content (precedence, partial-FY caveat, units, source, cost). It is long for a 3-param tool and could be tightened, but almost nothing is 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?

Despite no output schema, the description discloses return-shape facets an agent needs (per-FY obligations, ten largest recipients, dropped_unresolved, newest FY first, leaderboard ordering, period_complete flag, tool_notes caveats). Nothing essential for correct invocation is 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% (baseline 3), but the description adds real meaning: the ticker-wins precedence rule, `limit` default 20 with hard cap 100, and that fiscal_year alone triggers the leaderboard shape. It stops short of describing the USD units per row beyond naming them, so 4 rather than 5.

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 the specific resource (federal-contract obligation history) and the two distinct output shapes (per-ticker FY series vs fiscal-year leaderboard), using a domain verb ('obligations', 'leaderboard'). An agent can immediately distinguish this from siblings like get_fundamentals or ol_filing_search.

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 explicitly defines the selection rule: one of `ticker` or `fiscal_year` is REQUIRED, and if both are supplied `ticker` wins. It also names the use case (government-revenue-dependence diligence) and warns that the leaderboard covers only the OL crosswalk, not all federal contractors.

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