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

Annotations only declare readOnlyHint/openWorldHint; the description adds substantial behavior the annotations cannot convey: it returns a URL and never the file, the link is returned even without entitlement, and the `locked` field discloses the cost. It also notes the report duplicates data available from other tools, which is non-obvious behavioral context.

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?

Front-loaded with the deliverable (the URL), then access conditions, then the scope limit. Every sentence carries distinct information — return type, routing, entitlement, and granularity — with no restatement of the name or 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?

No output schema exists, and the description compensates by describing the return value (a URL plus a `locked` cost field) rather than the document itself. Combined with entitlement rules and the postal-area-only scope, an agent has everything needed to call and interpret the result.

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 year/place/language are already documented and the baseline is 3. The description adds one genuine semantic constraint beyond the schema: `place` must be a postal area, not a municipality, which is not stated in the parameter description.

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 verb and resource — 'the download link for one postal area's printable PDF report' — and immediately scopes it ('composite scores, trends and the full statistics table'). It also separates itself from siblings by naming get_place_stats as the tool for answering questions rather than fetching the document.

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?

Explicit routing: 'offer the link when someone wants the document, and answer questions from get_place_stats instead.' It also states a hard eligibility boundary ('Reports exist per postal area only, not per municipality') and the access condition (Suomiatlas Pro or an Area Pass), which is exactly the when/when-not guidance an agent needs.

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