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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), so the bar is lower. The description adds real context beyond them: the catalog is intentionally partial, the return payload includes release hash and attribution, and pagination exists. It does not state rate limits or snapshot freshness, which are the remaining unknowns for a data-snapshot tool.

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 tightly packed sentences that are front-loaded with purpose and then scope, usage, and boundaries. Every sentence earns its place; the return-field enumeration is slightly dense but justified since 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 carries the return-value burden and does so by enumerating the payload (series IDs, slugs, table/line metadata, units, adjustment basis, release hash, attribution). Combined with the scope caveat and usage examples, an agent has everything needed to call it 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%, so every parameter (limit, query, offset, category, response_format) is already documented in the schema, including defaults and enum values. The description adds no syntax or filtering nuances beyond the schema, so baseline 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?

Names a specific verb pair (list and search) plus the exact resource: a curated catalog of aggregate U.S. balance-sheet and debt series in a self-hosted Z.1 snapshot. It also sharply delimits scope with 'deliberately small' and 'This is not the full Z.1 universe,' so an agent can distinguish it from the broader fed_z1_series/fed_z1_snapshot siblings.

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 selection cues: example queries ('what household balance-sheet measures are available?', 'find the mortgage debt series') and the workflow hint 'resolve a series before another Z.1 call.' It stops short of naming the specific alternatives (fed_z1_series, fed_z1_change, fed_z1_snapshot) or stating when not to use it, so it is strong but not fully explicit.

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