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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint, so the safety profile is covered. The description adds that the result is the set of content versions produced by edits, but says nothing about ordering, retention limits, or whether the requirement is an existing message.

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?

Extremely tight and front-loaded: the action is stated first, then the scope. The second line is a fragment and mildly redundant with the title, but no sentence is wasted.

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 simple one-parameter read tool with no output schema, the description conveys the general shape of the result (versions from edits) but omits ordering and pagination behavior, and gives no help on the required id. Adequate but with clear gaps.

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% for the single required messageId parameter; the only hint is the Cuid2 pattern. The description adds no meaning about what the id refers to, its format, or whether it must belong to the calling user's workspace, so it fails to compensate for the coverage gap.

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 (get message history) and the second line clarifies scope: every version of the content, derived from edits. That implicitly separates it from messages_get, which returns the current message. It stops just short of naming that sibling explicitly.

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 alternatives named. The agent must infer from the scope phrase that this is for edit history rather than current content, but nothing routes it against siblings like messages_get or messages_edit.

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