message_history

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

With no annotations, the description carries the full behavioral burden. It usefully discloses ordering ('oldest first') and the recorded fields (who, when, note/reason), and 'audit trail' implies a read-only operation. However, it says nothing about access/permission requirements, pagination or result limits, or behavior on an unknown message_id, so the disclosure is partial.

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?

The core purpose is front-loaded in a dense but efficient first sentence. The second sentence, about work_status being retroactively counted for ownership and the stop hook, is a long internal-implementation aside of uncertain value to an agent selecting the tool, which dilutes conciseness.

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?

Since an output schema exists, the description need not enumerate return values, and it adequately conveys what the tool surfaces (event types, actor, timestamp, reason, ordering). For a one-parameter read tool this is nearly complete, with the only gap being when to prefer it over sibling lookups.

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% and the single parameter (message_id) is never addressed in the description. The parameter is largely self-explanatory from its name and context, so meaningful re-explanation is barely needed, but the definition does not compensate for the coverage gap. A baseline 3 is appropriate.

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 states a specific resource (the lifecycle/audit history for 'a message') and enumerates the event kinds it covers: resolve/reopen/work_status transitions, body revisions, and supersedes. This lets an agent distinguish it from sibling reads like get_thread or list_messages. It stops short of naming a sibling it is not, so it lands at 4 rather than 5.

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?

There is no explicit when-to-use guidance and no routing to alternatives (e.g., get_thread for thread context, list_messages/search_messages for message bodies). The content enumeration implies its purpose but never states the condition under which an agent should call it. This mirrors the MID calibration where descriptive content alone yielded a 2.

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