Search the series catalog

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

Beyond the readOnlyHint annotation, the description discloses case-insensitive search behavior, the fields searched, the contents of the returned candidate series (units, coverage, verification status, license), and the special datasetMatches behavior including on-first-call fetching. This gives the agent a clear model of what will happen.

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?

The description is compact and front-loaded with the core capability, followed by a high-value explanation of the return behavior. Every sentence adds useful information, and there is no filler.

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 compensates by summarizing the return shape (candidate series fields and datasetMatches). It provides enough context for an agent to decide and invoke the tool, though it doesn't describe edge cases like empty result behavior or pagination beyond what the schema already covers.

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 100%, so the baseline is 3. The description adds extra meaning by explaining that the query is case-insensitive and what fields it matches, plus concrete examples. It doesn't add much about limit/offset/source, but the schema already documents those adequately.

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 verb ('Find'), the resource ('series across ALL sources'), and the exact scope of the search (series ids, indicator names, geographies, dataset titles). It gives concrete examples and explains what is returned, which distinguishes it from siblings like list_sources or get_series.

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 conveys the intended use case clearly: it is the fast path from a question to the exact series id to fetch or pin, and it searches across all sources in one call. It does not explicitly name alternatives or state when not to use it, but the context is strong enough to guide tool selection.

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