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

Annotations already declare destructiveHint=true and openWorldHint=true, yet the description goes further: it names exactly what is destroyed (this Mac's cached chat copy), what leaves the list (an add_account entry), what survives (phone chats), and the functional consequence (WhatsApp tools stop working until re-connect). That is the precise extra context the annotation bar asks for.

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?

Front-loaded with the core action and the key side effect, then the parameter rule. Four sentences with no filler, though the account/confirm clause could be trimmed since the schema covers it.

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?

With an output schema present and full schema coverage, the description only needs to carry behavior — which it does: destructiveness, scope, side effects, and recovery path. Nothing an agent needs before calling is missing.

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 coverage is 100% and the schema itself already states 'Required when more than one account is linked', so the description's account guidance largely restates structured data. It adds nothing about the `confirm` parameter, and no format detail (label vs. id) beyond what the schema says.

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?

States a specific verb+resource ('Unlink WhatsApp from Local MCP — logs out the linked device on this Mac') and explicitly scopes it to this Mac, distinguishing it from the connect sibling. An agent can tell immediately what the tool does and what it does not do (chats stay on the phone).

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?

Gives clear operational context: it is the inverse of whatsapp_connect, WhatsApp tools stop working until that is re-run, and account must be supplied when several accounts are linked. Lacks an explicit 'when not to use' or a named alternative for removing an account vs. simply logging out, but the routing context is strong.

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