Fred Series Observations

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

Annotations already cover the read-only/idempotent/non-destructive profile, and the description adds genuinely non-obvious vintage semantics: without realtime parameters you get today's latest revision, which may differ from historical vintages. It says nothing about pagination behavior with the 1000-record default limit or what mode='delta' / source_checkpoint do.

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 core purpose and followed by the default/override rule and the sibling pointer. No filler; the only minor inefficiency is that the second sentence does not also fold in the limit or mode semantics an agent will need.

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 no explanation, but for an 8-parameter tool with zero schema description coverage the description leaves delta mode, checkpointing, and pagination entirely unexplained. An agent could call it, but would likely mis-set limit/offset or ignore mode.

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 coverage is 0%, so the description must carry parameter meaning, and it only covers three of eight: series_id vs. alias, plus realtime_start/realtime_end including the YYYY-MM-DD format. It is silent on mode (the sole enum), limit/offset pagination, and source_checkpoint, leaving most parameters cryptic.

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 names the resource (observations for a FRED series) and the two lookup keys (raw series_id or named alias), which lets an agent distinguish it from siblings like fred_series_vintage_dates. The verb is nominal rather than explicit ('Observations for...'), but the intent — retrieve time-series data points — is unambiguous.

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?

It states the default behavior (today's latest revision) and the condition for overriding it (pass realtime_start/realtime_end to pin a vintage), and routes the single-date case to fred_series_observations_asof by name. It does not advise when to use alias vs. series_id or when the sibling alias-listing tool is needed, leaving a small gap.

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