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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering safety and side effects. The description adds useful operational context by stating the data source (px.hagstofa.is) and that no auth is required, which goes beyond the annotations without contradicting them.

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 three tight sentences: purpose with output contents, usage sequence with the sibling tool, and an example path plus data source/auth. Everything earns its place; no filler or redundant restatement of the title.

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 single-parameter metadata lookup with a rich output schema and comprehensive annotations, the description covers the purpose, the expected return artifacts, the workflow order relative to table_query, a concrete example, the data source, and auth requirements. Nothing an agent needs to invoke it correctly is missing.

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?

The schema already fully describes table_path (100% coverage), so the baseline is 3. The description adds a concrete example path with an explanation of the population key figures, and it reinforces how the returned values feed into iceland-statistics.table_query, giving the parameter more practical meaning than the raw schema alone.

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 states the specific verb 'Get metadata' and resource 'Iceland statistics table', then enumerates the contents: title, dimensions, valid value codes, and latest update timestamp. It also differentiates itself from the sibling tool iceland-statistics.table_query by explicitly saying to use this one first for filter discovery.

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?

Explicitly instructs 'Use this BEFORE iceland-statistics.table_query to discover accepted filter values', naming the alternative and the workflow order. It also provides a concrete example path for the table_path parameter, leaving no ambiguity about when and how to use it.

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