nex_mail_message_detail

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

Adds substantial context beyond the single readOnlyHint=false annotation: the call mutates state by marking the message read, expired mailboxes fail, and the body is untrusted with instructions that must not be followed. The attachment-metadata-only note sets expectations on payload scope.

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 sentences, each carrying distinct load: action, identifier semantics, failure condition, security guidance. Front-loaded with the action and no filler.

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 no output schema and no annotation detail, the description supplies the essentials an agent needs to call it safely and correctly. It only lightly gestures at return content ('body', 'attachments are metadata only') without indicating other fields such as subject or sender.

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 0%, so the description carries the full burden and does so: id is the local mailbox ID, mailId is the numeric ID originating from nex_mail_message_list and explicitly not the RFC Message-ID. Both required parameters are given unambiguous meaning.

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 ('Read one synced email') plus the side effect ('mark it read'). It also disambiguates the resource from the sibling lister by naming nex_mail_message_list as the source of mailId.

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?

Clearly routes the agent: mailId must come from nex_mail_message_list and is never the Message-ID, and expired mailboxes are rejected. It gives the preconditions for a successful call but does not state when to prefer a different tool over this one (e.g. bulk listing).

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