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

Annotations already declare non-read-only, idempotent, non-destructive behavior. The description adds meaningful context beyond them: it supports either reading or partial updating, says to pass only fields that should change, and clarifies that it operates on the personally signed-in user rather than a business.

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 front-loaded with the core read/update behavior, then adds usage context and sibling differentiation. Every sentence contributes to correct tool selection or invocation, with no redundant restatement of the name or title.

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 profile tool with no output schema, the description covers the main fields, read/update modes, and sibling alternatives. It does not describe what an update returns or whether read responses are shaped differently, which is a minor remaining 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?

Schema description coverage is 100%, so the baseline is 3. The description still adds useful invocation semantics by explaining partial updates and that passing no fields performs a read, which is not fully captured by the schema alone.

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 or update the signed-in user's own profile. It lists the profile domains covered (name, email, phone, language, contact channel) and explicitly distinguishes the person from a business, naming sibling tools for the business case.

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 gives clear when-to-use guidance: learn what contact details booking can reuse. It also names explicit alternatives, owner_status and owner_update_business, for business details, and explains the read-vs-update invocation pattern.

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