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

Goes beyond the readOnly/idempotent annotations by disclosing truncation semantics (at most max_rows rows, full selection at the download URL), the total count, and the legal obligation to convey the citation. It does not mention rate limits or performance cost of large selections, but the important behavioral traits are covered.

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 tight sentences, front-loaded with what the tool returns first and the citation obligation second. No filler, though the parenthetical filter list is a light restatement of the schema fields.

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?

Return values need not be explained because an output schema exists, and the description still covers the truncation/download contract and the citation mandate. The remaining gap is routing guidance among the many sibling tools and coordinate-bounds semantics for a 13-parameter tool.

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 54%, and the description does not add much: it names the filter groups (box, time, station, cruise, height, QC) but gives no semantics for the four coordinate bounds, which are undocumented in the schema, nor clarification of exclusivity/format. Baseline 3 given partial coverage and only a high-level restatement of the filters.

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 verb+resource: observations for a single variable with named filter dimensions, plus the fact that it returns a truncated table, a total, and a download URL. It is clearly distinguishable from aggregate/estimate by returning raw observations, though it never says so explicitly.

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?

Usage is implied by the mention of max_rows/truncation and by the required id coming from search_variables (in schema), but the description never says when to choose this over aggregate (summaries), estimate (gridded products) or find_stations. No exclusions or prerequisites are stated.

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