List WhatsApp accounts on this server

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

Annotations already declare readOnly, idempotent, non-destructive and openWorld, so the safety profile is covered. With no output schema, the description adds real behavioral value by naming the returned fields, including that phones are masked and that write permission is exposed, plus the note that account_id is effectively ignored for listing.

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?

Three tight sentences with the resource and field list front-loaded, followed by routing guidance and the argument note. Nothing is wasted, though the clause about account_id being ignored is slightly at odds with the schema's resolution wording and could be sharper.

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 zero-required-argument read tool with no output schema, the definition covers what is returned, when to call it, and how to chain account_id into other tools. Pagination or account-limit behavior is not mentioned, but for an account registry that is a minor 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 schema already documents account_id (default, work, resolution from chat_id/message_id). The description adds a nuance the schema does not state plainly: that account_id is ignored for this listing call, clarifying that it does not filter results.

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 and resource ('List every configured WhatsApp account') and enumerates the returned fields (id, name, connection status, masked phone, owner, write permission), so an agent knows exactly what the tool produces. No sibling tool overlaps this listing behavior, so differentiation is implicit but 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?

Gives explicit sequencing guidance: 'Call this first when more than one account is linked, then pass account_id on the other tools.' That is clear context for when to use it, though it offers no exclusions or naming of an alternative listing path (e.g., resolving accounts implicitly elsewhere).

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