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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so the safety profile is covered. The description's only added behavioral value is stating the two supported transit systems; it says nothing about result limits, ranking, or matching behavior beyond 'name or code'.

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 short sentences, front-loaded with the core action and free of filler. Nothing extraneous, though there is room to fold in usage routing without bloating.

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?

An output schema exists, so return values need no explanation, and the tool is a simple two-parameter search with full annotation coverage. The remaining gap is the absent guidance on when this tool should be chosen versus its many siblings.

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 50%: query is documented, but the city enum (dc/nyc) has no description. The description partially compensates by mapping those systems to DC Metro and NYC Subway and by clarifying that query matches 'name or code', which is real added meaning over the bare enum.

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 ('Search') plus resource ('transit stations') and names the searchable fields (name or code), with the supported coverage (DC Metro, NYC Subway) scoping the tool. It implicitly separates itself from search_sfbay_stations by naming the DC/NYC systems, but never names that sibling explicitly, so differentiation is left partly to inference.

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?

No when-to-use or when-not guidance and no alternatives named. The agent must infer from 'DC Metro and NYC Subway' that this is not for SF Bay, and there is no hint about choosing this over get_all_stations or get_stations_by_line.

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