reopen_message

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

With no annotations, the description carries the full burden — and covers mutation effects, side effects (records who/why), idempotency (no-op for open message), and a constraint (4000 character limit). This exceeds the minimum viable disclosure.

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 dense sentences, front-loaded with the core action and followed by the most decision-relevant behavioral details. No filler or repetition.

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 two-parameter mutation tool with an output schema, this description covers the state transition, permission nuance, side effects, idempotency, and a length constraint. Nothing an agent needs to invoke the tool correctly is missing.

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 adds meaning about the reason parameter's purpose (who reopened and why) and its 4000-character constraint, but message_id semantics are left entirely to the schema's name and type.

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 precise verb and resource: 'reopen a resolved action_required message' and adds scoping details ('Either party may reopen, not just the author') that distinguish it from its resolution siblings. The intent is unambiguous and clearly not confused with resolve_message or confirm_resume.

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 says when the tool should be used — when a resolved message needs to be reopened, especially when the executor finds their fix incomplete. It does not explicitly name an alternative tool, but the guidance is explicit enough that an agent can decide correctly.

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