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

Annotations already declare readOnly/idempotent/non-destructive/openWorld, so the safety profile is covered. The description adds genuinely non-obvious behavioral context: values come from a self-hosted release snapshot, carry a source hash and release provenance, and are aggregate historical estimates subject to revision.

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-loaded with the core action, then payload, then examples and caveat. Three sentences with almost no waste; the enumerations are long but each item (units, SA basis, provenance) is informative rather than 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?

With no output schema, the description takes on the burden of describing returns and does so by listing the returned fields (identifiers, dollar values, units, SA basis, pagination, source hash, provenance). Combined with the revision caveat, an agent has enough to call and interpret the tool; only pagination mechanics and period-default behavior remain undocumented.

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 every parameter (series, limit, offset, start/end_period, response_format) is already documented, including the pointer to fed_z1_catalog for series discovery. The description adds no additional parameter syntax or constraints beyond what the schema supplies, 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?

The description states a precise verb and resource: returning a bounded quarterly history for one curated Fed Z.1 aggregate series, with the payload enumerated (ids, values, units, SA basis, provenance). It implicitly contrasts with siblings like fed_z1_snapshot/fed_z1_change through 'quarterly history,' but it never names them, so differentiation requires inference.

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 usage is given via three example phrasings ('household net worth since 2019', 'quarterly federal debt outstanding', 'consumer credit history'), which tells an agent when this is the right tool. It stops short of naming alternatives or stating when-not to use it; discovery of valid series is delegated to the schema note pointing at fed_z1_catalog.

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