Fred Series Observations Asof

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

Annotations already declare read-only, idempotent, open-world, non-destructive, so the safety profile is covered. The description adds real semantics beyond that: data is frozen at the vintage and revisions published later are excluded, which is exactly the behavior an agent must understand before trusting a backtest.

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?

Two short sentences, front-loaded with the identifying noun phrase and followed by the motivating use case. The literal backticks around vintage_date are a minor formatting artifact of scraped docstrings, but nothing is padded.

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?

An output schema exists, so return values need not be described. However, for a 5-parameter tool with zero schema documentation, the description should still tell the agent how series_id and alias combine and how pagination behaves; that omission leaves the call signature under-specified.

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 0% across 5 parameters, yet the description only explains vintage_date. The critical ambiguity — whether to supply series_id or alias and whether both are allowed — plus the limit/offset pagination defaults (1000/0) are undocumented in both the schema and the description.

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 retrieval action and its distinguishing qualifier: ALFRED point-in-time observations 'as known on vintage_date'. That is functionally different from the current-vintage sibling fred_series_observations, though the description never names that sibling to make the distinction explicit.

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?

The backtest framing ('reconstructs what a point-in-time backtest would actually have seen') implies when to reach for this tool, but the routing decision against fred_series_observations (current data) or fred_series_vintage_dates (available vintages) is left for the agent to infer rather than stated.

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