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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, destructiveHint=false) and openWorldHint, so the description's burden is lighter. It adds a meaningful non-structured trait — that the result set is large — which is exactly the behavioral context that steers tool selection. It stops short of quantifying size or noting any pagination/rate limits.

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, zero filler, with the primary purpose front-loaded and the disambiguation immediately after. Every clause earns its place.

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-value detail is unnecessary, and annotations carry the safety profile. Scope, result size, and sibling routing are all covered; nothing needed to select or invoke the tool is missing.

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%, but there is only one parameter and its enum values (dc, nyc) are self-explanatory in the schema. The phrase 'for one city' confirms the city scopes the result, adding modest meaning without describing the enum or any constraints.

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?

The description states a specific verb and resource ('Get the complete list of transit stations') plus scope ('with coordinates for one city'), so the agent knows exactly what comes back. It also names two siblings (search_stations, get_stations_by_line) as the targeted alternatives, cleanly separating this bulk-list tool from them.

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?

Explicit routing guidance: 'Large result; prefer search_stations or get_stations_by_line when looking for specific stations.' This gives both the condition (looking for specific stations) and the named alternatives, so no inference is required.

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