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 context beyond those annotations by detailing the return payload (table title, last-updated timestamp, array of variables with codes, names, valid values, and labels) and by noting this is a required prerequisite for querying. 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 three sentences and front-loaded with the core purpose. The workflow sentence earns its place, though the common table IDs are somewhat redundant with the schema's parameter description. It is not overlong and is well-structured for an agent to parse.

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 retrieval tool with a rich output schema, the description covers everything an agent needs: what the tool returns, how to obtain the table_id (via ssbnorway.data.search), and the exact sequence in the overall data-retrieval workflow. The output schema handles return-value details, so nothing critical 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?

Schema description coverage is 100%, and the schema description for table_id already explains that it is a numeric string from ssbnorway.search and lists common table IDs. The description repeats those common IDs and the workflow, which adds little beyond the schema. Baseline 3 is appropriate since the schema already carries the parameter semantics.

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 uses a specific verb and resource: 'Get the full metadata for a specific SSB table — dimension codes, valid value codes, and human-readable labels needed to construct a data query.' It clearly defines what the tool returns and explicitly distinguishes it from its siblings by name (ssbnorway.data.search and ssbnorway.data.query) through the workflow explanation. This lets an agent tell it apart without inspecting schemas.

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 explicitly states the exact position of this tool in the user journey: 'This is the required second step before querying data: call ssbnorway.data.search to find a table ID, then ssbnorway.data.metadata to learn the dimension codes and valid values, then ssbnorway.data.query to retrieve actual data.' It names both the predecessor and successor tools, leaving no ambiguity about when to use it versus alternatives.

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