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

Annotations already declare readOnlyHint and openWorldHint=false, so safety is covered. The description adds genuinely useful behavior beyond that: results are country-wide rather than local, and suppressed areas are omitted, meaning absence signals 'unmeasured' not 'dissimilar' — a subtlety an agent would otherwise misread.

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 core definition, then supporting nuance about statistical vs geographic and the suppression caveat. Four sentences, each carrying weight, though slightly long for the payload.

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, but the description covers what the results mean (spread nationally, absence due to suppression), which is the key ambiguity for this tool. Combined with the fully-covered input schema and safety annotations, an agent has enough to call it correctly.

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 place, year, and limit are already documented in the schema (including formats, defaults, and the limit bounds). The description adds the notion of a 'whole statistical profile' but no per-parameter meaning beyond the schema, so the baseline 3 applies.

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 operation (find postal areas most statistically like a given one) with explicit scope across a whole statistical profile. It distinguishes itself from siblings like get_nearby_places by clarifying 'similarity is statistical, not geographic,' so an agent can route correctly without opening 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?

Gives a concrete use case ('where else in Finland feels like this neighbourhood?') and implicitly contrasts with geographic siblings. It stops short of explicitly naming an alternative tool or stating when not to use it, so it is clear context without full routing guidance.

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