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

Annotations already establish this is a read-only, idempotent, closed-world lookup, so the safety profile is covered. The description adds genuinely useful behavior beyond that: the exact payload it produces and the empty-result case when park-and-ride isn't warranted, which an agent needs to interpret a null response correctly.

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?

One dense sentence, but it is front-loaded with the purpose and then ordered as trigger, output contents, and empty-case behavior. No filler, though the parenthetical example list makes it longer than strictly necessary.

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?

With no output schema, the description carries the return-value burden and does so by enumerating the fields returned. The main remaining gap is input guidance for a tool with zero required parameters and two undocumented coordinates.

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 only 33% (only 'address' is documented) and the description adds nothing about inputs. It never clarifies whether lat/lon or address should be supplied, how they interact, or what the coordinate bounds mean, leaving two of three parameters unexplained in both schema and prose.

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: suggest where to park outside the busy area and ride the streetcar in, enumerating the outputs (boarding stop, line, next departures, ride time, final walk). This is clearly distinguishable from siblings like find_parking or check_parking, which deal with parking itself rather than a park-and-ride itinerary.

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 clear trigger condition ('For a hard-to-park New Orleans destination') with concrete examples (French Quarter, CBD, Superdome, Convention Center), plus a negative condition ('returns nothing when parking at the destination is easy enough'). It does not explicitly name sibling tools as alternatives, so it stops short of a 5.

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