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

With no annotations, the description carries the full burden. It discloses the partial-update behavior ('Only the fields you pass are altered') and warns about the id distinction. However, it omits details on errors, idempotency, or return values. For a simple update tool, this is adequate but not rich.

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 concise sentences, front-loaded with the main purpose, followed by a usage prerequisite and a caution. No waste; every sentence 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?

For a partial-update tool with one required parameter, the description covers the essential: what it does, how to obtain the ID, and the partial-update behavior. It lacks return-value or error details, but those are not critical for an update operation. The absence of an output schema and annotations is partially mitigated by the clear usage guidance.

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 64%, so the schema documents many parameters. The description adds the key semantic that only passed fields are altered, and clarifies the addressId vs contactId confusion. It does not describe the parameters missing from the schema, but it compensates somewhat for the update behavior.

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 clear verb and resource ('Change one address') and distinguishes it from sibling tools like addresses_create and addresses_delete. It also clarifies the partial-update semantics, making the tool's purpose unambiguous.

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 explicitly instructs to use addresses_list first to obtain the addressId and warns that address id is not contact id. This provides a clear prerequisite and a common pitfall, though it doesn't explicitly state when not to use the tool (e.g., for creation). The sibling list makes alternatives obvious.

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