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

Annotations declare non-read-only, non-destructive, idempotent, and closed-world behavior, so the description needn't repeat safety. It adds valuable context beyond annotations: an upsert-by-label model, a cap of 10 locations, and notes for the rider. It omits what happens when the limit is reached and whether a new save can overwrite, which are minor but notable.

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 three sentences, front-loading the core action and then adding the update-by-label nuance, the 10-location limit, and the notes purpose. Each sentence adds information, though the order is slightly non-linear (limit after update). No filler.

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 four-parameter mutation with full schema coverage and annotations covering safety, the description covers upsert, quota, and notes meaning. It lacks explicit guidance on what happens at the 10-location cap and does not mention makeDefault, but overall it gives an agent enough to call correctly.

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 the schema already documents all four parameters. The description adds the meaning of notes and the label-as-identifier behavior, which complement the schema, but makeDefault is not mentioned in the description. Baseline 3 applies since the schema does the heavy lifting.

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 (saves) and resource (delivery location) and scopes it to the connected person's WaitApp account. The purpose is unmistakable and distinguishes the tool from siblings like delete_saved_location or place_delivery_order.

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 implies usage by saying saving a label updates an existing location and that later orders can use it, but it does not explicitly state when to use this tool versus alternatives or prerequisites such as an established connection. It offers no exclusions.

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