Get observations (with provenance)

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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds meaningful behavioral detail beyond that: every value carries provenance (source URL, retrieval time, connector version) and the envelope includes verification status and citation, which helps set expectations for the return payload.

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 sentences with no redundancy. The core purpose is front-loaded, and the window-control behavior is placed within the same compact description.

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?

Given no output schema, the description does a good job of summarizing the return shape (values with provenance, envelope with verification/citation). It is adequate for a read-only retrieval tool, though it omits details like ordering, error cases, or how source relates to seriesId.

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 60%, so the description is not the sole source of parameter meaning. It adds useful window-control semantics ('defaults to the latest 60 points' and 'start/end (YYYY-MM-DD)') but says little about the required source and seriesId parameters beyond implying 'one series'.

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 clearly states the tool returns observation values for one series, with a specific resource ('observations') and a scope ('one series'). It does not explicitly contrast with related tools like get_series or get_series_stats, so it stops short of full 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?

The description gives concrete usage context: defaults to the latest 60 points and explains how to control the window using start/end or latest. It does not mention when to prefer this tool over siblings, but the window-control guidance is clear and actionable.

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