Route geometry

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

Annotations already declare readOnlyHint and openWorldHint, so safety is covered. The description adds genuinely useful behavior beyond that: geometry is simplified to the requested point budget, endpoints are preserved, and only Attica (OASA buses, trolleys, metro, tram) is covered. It stops short of saying what happens for out-of-coverage or unknown route codes.

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 sentences, front-loaded with the identity of the resource, followed by the default-vs-override guidance. No filler; every clause carries actionable information (default rationale, override condition, simplification behavior, geographic scope).

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?

There is no output schema, so the description carries the burden of explaining returns, and it does so at a high level (summary stats, coord pairs, GeoJSON LineString). Coverage limits and simplification are stated; edge-case behavior (invalid route code, non-Attica routes) is left implicit, which is a minor gap for a 3-param read tool.

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 coverage is 100%, so the baseline is 3, but the description adds meaning the schema does not: it explains why 'summary' is the default, that max_points only applies to geometry requests, and that simplification preserves endpoints. This clarifies the interaction between format and max_points rather than merely restating 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?

States a specific verb+resource ('The geographic path of one OASA route') and immediately scopes it by operator and geography. It is clearly distinguishable from siblings like route_stops and line_routes, which deal with stop sequences rather than geometry.

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 prescribes the default ('Defaults to a summary ... because raw shapes run to hundreds of points') and the condition for overriding it ('request "coords" or "geojson" only when the geometry itself is needed'). This is exactly the when-to-use guidance an agent needs to avoid over-fetching.

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