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

Annotations already establish the safety profile (readOnly, idempotent, non-destructive, closed-world), so the remaining burden is light. The description usefully discloses the returned payload shape (value, period, methodology, official source) — information that exists nowhere else, since there is no output schema.

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?

One sentence, front-loaded with the resource and then the returned fields. No waste, though the trailing ellipsis-format category list is slightly loose compared to the schema's fixed enum.

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?

Adequate for a zero-required-parameter lookup: the payload is described and the schema covers all inputs. It falls short on routing (no differentiation from cost_of_living/search) and on hints about how key and category interact or what happens when a statistic is not found.

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%, so all four parameters (key, category, locality, overview_only) are already documented in the schema, including the fallback behavior of locality. The description adds nothing beyond that baseline, which is the expected 3 when the schema does the work.

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 resource (verified Malta statistics) and enumerates the domains covered (population, economy, prices, housing, climate), so an agent knows exactly what data it returns. It does not, however, distinguish itself from the sibling cost_of_living or search, which overlap in subject matter.

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 no when-to-use guidance, no prerequisites, and never mentions the alternatives (cost_of_living, search, fetch). An agent must infer from the name alone that this is the general-purpose statistics lookup rather than the cost-of-living tool.

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