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

Annotations already declare readOnly, idempotent, openWorld, and non-destructive, so safety is covered. The description adds the useful default behavior (returns everything when unfiltered), but says nothing about pagination, rate limits, or result size for a potentially large stop list.

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 tight sentences, front-loaded with the resource and immediately followed by the filter behavior. No filler, nothing to trim.

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 structure need not be explained, and annotations cover the safety profile. For a simple optional-filter read tool the description is nearly sufficient; only minor gaps about unfiltered result size or partial-param behavior remain.

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 100%, so all three params are already documented in the schema. The description only restates the lat/lon/radius filter concept without adding units, combinations (all three together?), or defaults beyond what the schema provides.

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 ('Get DC Metro bus stops') and even names the retrieval modes (all vs. geographic filter). It distinguishes itself from station/position siblings by scoping to bus stops, though it never explicitly contrasts with 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?

'Returns all stops or filters by lat/lon/radius' implies when the optional params matter, but there is no explicit when-to-use guidance, no mention of prerequisites, and no reference to alternatives like search_stations or get_bus_routes.

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