iris_get_message

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

With no annotations, the description carries the full behavioral burden. It explicitly discloses truncation via max_chars, that attachment contents are not downloaded, that the message is not marked read, and that the body is untrusted data. These side-effect and safety details are exactly what an agent needs beyond the schema.

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?

Two sentences with no filler. The most decision-relevant facts are front-loaded, and every clause adds behavioral or semantic value.

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 low-complexity tool with an output schema present, the description covers all essential invocation facts: what is read, truncation behavior, attachment handling, read-status side effect, and a trust boundary. Nothing needed to call it correctly is missing, aside from routing/prerequisites already penalized in Usage Guidelines.

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 0%, so the description must compensate. It gives clear semantics for max_chars ('truncated at max_chars') but message_id is only implied by 'one message' and is never explained in terms of provenance or format. The compensation is partial, leaving a gap for message_id.

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 opens with a specific verb-resource pair ('Read one message in full') and enumerates exactly what is returned: headers, plain-text body, and attachment names/sizes. This clearly differentiates it from sibling list/search/get_thread tools even without naming them, since it scopes to a single full message.

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?

The description implies the tool is for retrieving full content of a known single message, but it does not explicitly state when to prefer it over iris_get_thread or iris_search_messages. It also does not mention prerequisites such as authentication or how to obtain a message_id, leaving routing partly to inference.

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