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

With no annotations, the description carries the full burden and does well: it discloses the ordering algorithm (nearest-neighbour from a start point), that distances are as-the-crow-flies, that links to records and any matching editorial route are returned, and what the default start point is. It does not explicitly state the operation is read-only with no side effects, nor what happens on empty result sets.

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?

Two tight sentences plus an example block: the core action and selection modes come first, the return shape second, and motivation examples last. Nothing is padding, and the examples earn their place by anchoring ambiguous itinerary phrasing.

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 an 8-parameter tool with no output schema, the description does the necessary work by describing the returned payload: ordered stops, crow-flies distances, record links, and matching editorial routes. The remaining gap is that the interaction between filters (intersection vs union) stays ambiguous under 'and/or', and no-result behaviour is unaddressed.

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 every parameter is already documented, and the description largely restates the filter dimensions (architect, city, collection, era, ids) rather than extending them. It does add the combination behaviour 'and/or' and the start-point semantics, but that is marginal over an already complete 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 — 'Plan a visit route through buildings' — and immediately scopes the corpus to the Baltic states and Finland. It is clearly distinguishable from the sibling search_* tools because it produces an ordered itinerary rather than a result list.

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?

Explicitly says 'Use it for itinerary questions' and supplies three concrete query examples (Riga day, Aalto route, Vilnius modernism walk), which gives an agent a clear trigger. It never states when NOT to use it, e.g. that plain lookups should go to search_baltic_finnish_architecture or get_architecture_record, so the routing to siblings is left implicit.

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