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

The description adds useful behavioral context beyond the annotations, specifically that null values or percentiles mean suppressed or unpublished data due to small-area confidentiality, not zero. The read-only and closed-world safety profile is already covered by annotations, so this confidentiality caveat is the main extra value.

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 with the core purpose front-loaded. The confidentiality caveat is relevant and earns its place, and there is no redundant filler.

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 comparison tool with no output schema, the description sufficiently explains the returned content as statistics with national benchmarks and percentiles. It also explains the key null-value behavior, though it does not describe response shape or pagination details.

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 the schema already documents the places and year parameters thoroughly. The description repeats that names or codes are accepted and reinforces the 12-area limit, but adds no extra parameter syntax or constraints beyond the schema.

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 a specific action and resource: side-by-side statistics for Finnish postal areas, including national benchmarks and percentiles. It is clear what the tool does, but it does not explicitly distinguish itself from siblings such as rank_areas or get_area_report.

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 implies the tool is for comparing multiple postal areas at once, with a maximum of 12. However, it does not explicitly state when to use this instead of related tools like get_place_stats or rank_areas, nor does it give exclusions.

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