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

Annotations already declare the safe read-only/idempotent profile, so the bar is lower; the description still adds real context by disclosing the returned evidence (vintage, caveats, CAGR-only-when-meaningful) and the point-in-time semantics of as_of_year excluding future observations from a historical calculation.

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 front-loaded sentences: operation first, outputs second, usage examples third. The output enumeration is slightly listy but each clause carries information; little waste.

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 appropriately enumerates the return components (observations, changes, CAGR, units, vintage, caveats) and covers indicator, geography, and as-of-year intent. Complete enough to call correctly, though it is silent on source coverage limits beyond the as_of_year note.

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 the baseline is 3. The description goes beyond the schema for as_of_year, explaining its purpose (preventing future observations from entering a historical calculation), which the schema only describes as a four-digit year.

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 precise operation ('Calculate prior-observation and exact five-year changes') on a well-scoped resource ('one official BEA SASUMMARY state indicator'). The single-indicator scope plus the enumerated outputs (component observations, absolute/percent changes, CAGR, units, vintage) make it distinguishable from multi-state siblings like bea_compare_states.

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?

Concrete trigger examples ('five-year Florida GDP trend', 'how has Ohio employment changed?', 'California real per-capita income growth') make the intended use clear. It does not, however, state when to prefer the sibling tools (e.g. bea_state_economic_history or bea_state_economic_profile) or any exclusions.

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