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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=true, but the description adds a meaningful operational detail: an 'all' search may download a 50 MB bus GTFS once. It also explains that the tool returns station/stop IDs for use with next_departures and trip_between, which is useful beyond the annotations.

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 description is front-loaded with the core action and then explains the system choices and download caveat without unnecessary wording. Every sentence contributes either selection guidance or operational context.

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 two-parameter lookup tool with an output schema, the description covers the key behavioral caveat and parameter meanings well. It could be slightly more complete by describing query matching behavior, but nothing critical is missing for correct invocation.

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 0%, so the description must carry parameter meaning. It explains that query searches by name and fully defines the system values ('nj_transit', 'nj_bus', 'path', 'all'), including the default behavior of 'all', though it does not specify matching semantics such as substring or case sensitivity.

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: 'Find stations/stops by name.' It also distinguishes the supported transit systems and ties the result IDs to downstream tools next_departures and trip_between, making its role clear among siblings.

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 selection guidance for the system parameter, including the important caveat that system='all' includes bus and triggers a one-time 50 MB GTFS download. It also tells the agent to use system='nj_bus' for bus-only searches and mentions downstream tools, though it does not explicitly state when not to use this tool versus lines or service_alerts.

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