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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint, so the safety profile is covered. The description adds genuinely useful context beyond that: the self-hosted release snapshot provenance, the fields returned (units, seasonal-adjustment basis, source hash, release provenance), and the important caveat that 'values are aggregate historical estimates that may be revised.' It does not discuss rate limits or snapshot staleness.

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 sentences, front-loaded with the core action followed by return contents and usage examples. Dense but each sentence carries information; the 'Includes...' enumeration is somewhat list-like but earns its place given there is no output schema.

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?

With no output schema, the description correctly compensates by enumerating returned fields and adds a revision caveat, so an agent knows what to expect. It is complete enough to call correctly, though it could have noted how to expand or validate the series identifier beyond the schema's pointer.

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% (limit, offset, series, start/end_period, response_format all documented), so the baseline is 3. The description alludes to 'bounded' history and 'pagination' but adds no syntax, default, or behavioral detail beyond what the schema already states.

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+resource: 'Return a bounded quarterly history for one curated Federal Reserve Financial Accounts (Z.1) aggregate series.' The word 'one' and 'curated aggregate series' implicitly separates it from a catalog/enumeration tool, but the description never names fed_z1_catalog, fed_z1_change, or fed_z1_snapshot to make the distinction explicit. Clear purpose, weak sibling differentiation.

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?

Gives concrete trigger phrasings ('show household net worth since 2019', 'quarterly federal debt outstanding', 'consumer credit history') that map well to the tool, establishing clear context. However it offers no exclusions or named alternatives, and the routing hint ('Call fed_z1_catalog to discover supported values') lives only in the schema, not the description.

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