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

Adds substantial context beyond the destructive/openWorld annotations: login requirement, ownership and timeout limits, the two-phase preview/confirm handshake with previewHash, side effects (clears references and related albums), and an explicit limitation (no guarantee the recipient hasn't read or saved it). This is exactly the extra behavioral detail annotations cannot convey.

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?

Front-loads the login requirement and packs the workflow, constraints, and caveats into a few dense sentences with no filler. It is terse to the point of being telegraphic, which slightly hurts readability but wastes nothing.

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 destructive, non-idempotent, open-world tool with 0% schema coverage and no output schema, the description covers everything an agent needs: prerequisites, allowed scope, the preview/confirm protocol, side effects, and known limitations.

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, and it does: it explains consent=true, preview=false, previewHash as the confirmation token, and the same-params requirement for the confirm call. conversationId is left implicit and the previewHash format is only in the schema pattern, so it is not exhaustive.

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 (recall my own message) and immediately bounds scope: only the caller's own messages and only within the timeout window. An agent can distinguish this from sibling delete/hide tools (delete_my_moment, hide_live_message) without opening the schema.

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?

Gives clear operational context: obtain messageId via read_messages, default call previews, and confirmation requires same params + previewHash, consent=true, preview=false. It names a prerequisite tool but does not explicitly name when-not-to-use or a sibling alternative for deletion, so it stops short of full routing guidance.

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