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

The annotations already declare that this is a non-read-only, open-world, non-idempotent, and potentially destructive operation. The description adds useful domain scope by limiting it to contact details, but it does not explain partial-update behavior, what 'destructive' means here, or any permission requirements.

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?

Two short sentences with no filler. The primary action is front-loaded and the sibling-tool guidance follows immediately.

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 mutation tool with 8 undocumented parameters and a destructive annotation, the description is too sparse. The output schema means return values need not be explained, but the lack of parameter and partial-update semantics leaves significant gaps.

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?

There are 8 parameters with 0% schema description coverage, so the description must carry the burden of explaining them. It only says 'contact details', which loosely implies fields like name, phone, and location, but does not clarify formats, optionality, or whether omitted fields are preserved.

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 uses a clear verb, 'Update', and identifies the resource as 'contact details', which an agent can distinguish from application-answer and preference operations. It stops short of explicitly saying it updates the profile record, but the intent is still clear.

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 explicitly routes the agent away from this tool for application answers, naming onboarding and preference tools as alternatives. It does not spell out every case for using update_profile, but the domain boundary is clear enough.

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