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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=false, so the safety and idempotency profile is clear. The description adds only the resource context ('saved addresses, like home or work') and does not describe permissions, pagination, or other behavioral details.

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 a single, front-loaded sentence with no wasted words. It gives the usage trigger and concrete examples efficiently.

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-only list tool with a single fully documented parameter, complete annotations, and an output schema, the description is largely sufficient. It could explicitly say it lists all saved addresses for the given contact, but the name, title, and schema fill that gap.

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?

The single parameter contact_id has 100% schema description coverage, so the schema already defines it as the contact's API id. The description mentions the contact but adds no further parameter semantics, making the baseline 3 appropriate.

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 identifies the resource clearly: a contact's saved addresses, with examples like home and work. It implies retrieval/list behavior, though it does not explicitly state the verb or distinguish itself from the sibling mutation tools (addresses.create/update/delete).

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?

It provides a clear usage trigger: 'When you need a contact's saved addresses.' The home/work examples make the context concrete, but there is no explicit when-not guidance or named alternative tool.

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