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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds genuinely useful behavior beyond annotations: it returns the ticker and the span each series actually covers, discloses coverage breadth (180 countries, some back to 1920), and explains that series cannot be listed — only searched. No contradiction with annotations.

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?

Five sentences, each earning its place: purpose with examples, coverage scope, return value plus downstream workflow, country parameter format, and a usage directive. The description is dense but efficient, front-loaded with the core purpose, and uses compact formatting (em-dashes, semicolons) without waste.

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 an output schema present, return-structure details are already covered. The description addresses search semantics, geographic and temporal coverage, the ticker+span return behavior, the next-step workflow, and the country parameter format. The only notable gap is the undocumented `limit` parameter, which is a minor omission for a search tool of this profile.

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%, so the description must carry the documentation burden. The `country` parameter is explicitly documented with format and examples ('Switzerland' or 'CHE'). The `query` parameter is only implicitly defined through the examples (CPI, commodities), not formally described. The `limit` parameter is entirely undocumented, leaving its behavior and default semantics unexplained.

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 opening clause 'Find a macro-economic series by name or country' names a specific verb, resource, and scope, followed by concrete examples (CPI, interest rates, equity indices) that pin down the domain. It also differentiates itself from the sibling get_macro_series by positioning this tool as the search entry point ('pass the ticker to get_macro_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?

'Search first: there are tens of thousands of series and they cannot be listed' is an explicit directive that tells the agent when this tool is the correct entry point. The instruction to pass the returned ticker to get_macro_series provides a clear workflow with the most relevant sibling. However, it does not explicitly mention when not to use this tool versus other siblings like get_indices or list_coverage.

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