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

Annotations declare readOnlyHint=true, and the description is consistent. It adds meaningful behavioral context beyond annotations: intentionally small chain rows, explicit exclusions (polygons, lifecycle, provenance, etc.), batch/throughput details for anonymous vs verified callers, and catalog coverage limits. This is rich, actionable behavioral disclosure.

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 main purpose and exclusions are front-loaded, followed by structured invocation and catalog context. The description is longer than minimal, but most sentences earn their place by conveying usage thresholds, alternative tools, and billing behavior. Minor redundancy exists around 'latest-available' and 'current catalog' details, but it is not bloated.

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 9-parameter endpoint with no output schema, the description communicates the return shape (loc_id, name, admin level, vintage when available), invocation rules, exclusions, and alternatives. It does not provide examples or mention every optional parameter (batch_id, request_id, country_hint), but those are already covered by a 100%-coverage schema, so the description is nearly complete for an agent to call the tool 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 the baseline is 3. The description adds substantial value beyond the schema by explaining when country_scope/target_admin_level must be set (above 25 points), how bulk_preset provides a cross-country fast path, and how exploratory calls may omit scope. It does not restate every parameter, which is appropriate given the schema already documents them.

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 opens with 'Compact reverse geocoding' and explicitly states the core action: 'Converts one WGS84 point, or a bounded point list, into the latest-available administrative loc_id chain.' It also names sibling-like alternatives (loc_id_info, get_geometry, compare_geographies) and enumerates what the tool does not return, so an agent can clearly distinguish it from neighboring tools.

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 gives explicit routing guidance: pass returned loc_ids to loc_id_info, use get_geometry for shapes, and compare_geographies for relationships. It also specifies when to omit scope, when country_scope and target_admin_level are required (batches above 25), when to split multi-country input, and when bulk_preset is the right alternative.

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