delete_group_message

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

Annotations already flag destructiveHint=true and idempotentHint=true, but the description adds real context beyond them: irreversibility, that older clients may silently ignore the delete, that repeating it has no further effect, and that the local store copy is retained. It also discloses the return shape ({status: 'deleted'}) since no output schema exists.

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-loaded with the core action, then routing, then parameter sourcing, then caveats and return value. Despite its length, every clause carries distinct information (version dependency, irreversibility, idempotency, local-copy retention) with no filler.

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 mutation tool with no output schema, the description covers everything an agent needs: safety profile (already in annotations, reinforced here), irreversibility, client-compatibility caveat, idempotency, parameter provenance, and the return value. Nothing material 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 coverage is 100%, so the baseline is 3, but the description adds provenance the schema lacks: group_id comes from list_groups, and target_timestamp is the ms timestamp of the caller's own message from send_group_message or get_conversation. That sourcing guidance exceeds what the terse schema descriptions ('Group ID', 'Timestamp of the message to delete') provide.

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 ('Remote-delete (unsend) a message you sent to a group') with precise scope ('removing it for all members on Signal 5.0+ clients'). It explicitly distinguishes itself from the three closest siblings (delete_message for DMs, admin_delete_message, delete_local_messages), so an agent can route correctly without opening any 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 explicit when-to-use-this vs alternatives: 'Use delete_message for DMs; admin_delete_message to delete another member's message as admin; delete_local_messages for local-only removal.' The selection condition for each alternative is named, leaving nothing to inference.

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