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 adds useful context beyond annotations: authentication and consent requirements, unit conventions, direction convention ('directions FROM'), and return metadata about source/freshness. It does not, however, disclose rate limits or error behavior.

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?

Three short sentences, front-loaded with purpose, then prerequisites, then units and return details. Every sentence contributes useful information without waste.

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 simple read-one tool with rich annotations and no output schema, the description gives enough to call it safely: auth requirement, units, and return metadata. The main gap is that it does not clarify the required trip id parameter. Overall, it is nearly complete for the tool's complexity.

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%, and the single nested parameter 'path.id' is not explained in the description. 'Read one saved trip' implies an identifier but does not state that the parameter expects a trip id, its type, or its minimum value. The description leaves parameter meaning to inference.

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: 'Read one saved trip.' This distinguishes it from siblings like list_my_trips, save_my_trip, update_my_trip, and delete_my_trip. An agent can immediately tell it retrieves a single saved trip.

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?

The description gives prerequisites ('Requires your Gillby account and explicit account consent'), which is useful context. However, it does not explicitly say when to use this tool versus list_my_trips or how to obtain the required trip id. Usage is implied but not fully guided.

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