Sync inboxes

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

Beyond the annotations (readOnlyHint=false, idempotentHint=false, destructiveHint=false), the description discloses two non-obvious behaviors: the required API key scope 'conversations:write' and that the operation runs synchronously, which matters for timeout planning. It also narrows the blast radius to accounts with open conversations, though it omits what happens on partial failure or how long a synchronous sweep may take.

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?

Four short lines, with the purpose and the scope filter front-loaded before the endpoint reference. The opening line duplicates the tool title verbatim, which is the only wasted text; the remaining lines each carry distinct information.

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 parameterless action with no output schema, the description supplies what an agent actually needs: the write scope, the synchronous nature, and which accounts are affected. An agent can call it correctly without further fields, though return/result expectations and failure behavior remain unstated.

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?

The tool takes zero parameters, so there is no parameter-level meaning for the description to add; the empty schema is fully specified by context. The baseline for a parameterless tool applies.

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 pairs the specific verb 'sync' with a precise scope: 'the inbox of every account that has an open (SENT/READ/REPLIED) conversation.' This clearly separates it from siblings like list_conversations or get_conversation, which read data rather than trigger a mailbox refresh, though it does not name those alternatives directly.

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?

Usage is implied rather than stated: an agent can infer this is the call to make when inbox data is stale for accounts with active threads. There is no explicit when-to-use or when-not-to-use guidance, no mention of cost or frequency limits, and no pointer to a cheaper alternative for single-conversation refresh.

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