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

Annotations declare readOnlyHint, openWorldHint, idempotentHint true and destructiveHint false, covering the safety profile. The description adds behavioral context beyond annotations: it notes that some indicators return a clear error message instead of raw data due to missing breakdown support, and that the call returns multiple periods. This is useful disclosure of a failure mode and return characteristic, and it does not contradict the 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?

The description is a single paragraph that front-loads the core purpose (fetching full time series) and then adds the caveat about region/sector breakdown. It is concise, with no redundant filler, and the key information is presented in order of importance. It earns a 4 for being efficient and well-structured without being overly terse.

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?

For a simple read-only tool with two parameters and no output schema, the description covers the main aspects: what it does, the types of data it covers, a potential failure mode with a clear message, and the source of the indicator ID. It does not describe the exact return format, but since there is no output schema and the description implies a series, this is adequate. The description is sufficiently complete for an agent to invoke it correctly.

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 100%, meaning both parameters (indicator_id and recent) are fully described in the schema with types, defaults, and examples. The description adds minimal extra meaning beyond reiterating that indicator_id comes from gastat_search or gastat_headline, which is already in the schema. It does not introduce new semantics beyond the schema, so the baseline of 3 applies.

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 fetches the full time series for a GASTAT indicator ID, emphasizing multiple periods for comparison rather than just the latest value. It mentions the coverage of various data types (population, employment, GDP, etc.) and distinguishes from the latest value, but does not explicitly compare to sibling tools beyond referencing gastat_search and gastat_headline as sources. The purpose is specific and actionable.

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 provides clear context for when to use the tool: when a time series across multiple periods is needed, not just a single value. It also gives an exclusion and alternative: if an indicator requires a region/sector breakdown not exposed by this call, it returns a clear message, and the user should retry with a different indicator from gastat_search. This gives explicit guidance on when to use and when to look elsewhere, though it does not directly mention gastat_headline as an alternative for single values.

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