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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, openWorldHint), so the bar is lower. The description still adds useful behavior beyond them: the data source and coverage scale, the exact fields returned (WGS84 coordinates, postal code, municipality, province, region), and the negative capability regarding POIs. No auth or rate-limit detail, hence not a 5.

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?

Three sentences, each earning its place: purpose, data source plus return payload, then the negative capability. The most decision-relevant fact (forward geocoding) is front-loaded and there is no 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 3-parameter read-only lookup with no output schema, the description supplies exactly what is missing: the source dataset, the returned fields, and the scope limitation. An agent has everything needed to decide to call it and to interpret results.

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 q, city, and limit with examples and bounds. The description only restates that search is by street name with optional municipality, adding no syntax or format detail beyond the schema. 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 verb and resource ('Forward geocoding for Italian addresses') plus the underlying dataset ('ANNCSU street archive, 18.7+ million addresses'). The word 'Forward' cleanly separates it from the sibling zornade_geocode_reverse, so an agent can route without opening either schema.

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 clear context for use (street name plus optional municipality) and an explicit exclusion: it does NOT find points of interest, with the corrective action 'search by street name instead'. It stops short of naming which sibling tool to use for POI or parcel lookups, so it is strong but not fully explicit about alternatives.

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