get_message

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

No annotations exist, so the description carries the full disclosure burden. It correctly declares 'Read-only', which is genuine safety context, but never mentions that the body can be silently truncated by max_body_characters (default 12000, cap 50000), nor authentication/permission requirements. Useful but incomplete for a no-annotation tool.

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 short sentences, zero filler, with the core action front-loaded and the sequencing hint and read-only flag following. Nothing could be cut without losing 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 4-parameter read tool with no output schema and full schema coverage, the definition is nearly sufficient. The one meaningful omission is truncation behavior (what happens when the body exceeds max_body_characters), which an agent would want to know before rendering results.

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 all four parameters including account, mailbox default, message_id provenance, and max_body_characters are already documented in the schema. The description adds no semantics beyond it, so the baseline 3 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?

States a specific verb+resource+scope: 'Read one message body by its id.' The word 'one' cleanly contrasts with the sibling list_messages/search_messages, which return many. It names those siblings, though only as a prerequisite rather than as explicit alternatives.

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?

'Use after list_messages or search_messages' gives a clear ordering/prerequisite that tells the agent when this tool is the right next step. It stops short of stating when not to use it, e.g. for metadata-only or bulk needs, but the context is unambiguous.

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