delete_local_messages

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

Annotations already flag destructiveHint=true, idempotentHint=true and readOnlyHint=false, but the description adds genuinely new context: nothing is unsent from Signal or removed from other devices, changes are irreversible locally, and the return shape is {deleted, status} with 0 when nothing matched. This goes well beyond the annotation surface.

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?

Purpose is front-loaded in the first sentence, then recipient semantics, then local-only scope, then alternatives. Dense but every clause carries information; the parenthetical return note is slightly cramped but earns its place.

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?

No output schema exists, yet the description supplies the return shape and the zero-match case, plus the destructive scope and alternatives. For a single-parameter destructive tool, nothing an agent needs 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 baseline is 3, but the description adds real meaning the schema lacks: recipient accepts E.164 phone number or group ID, and using your own number deletes only note-to-self messages. That special-case behavior is not in the schema.

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+resource+scope: 'Delete the locally stored messages of one conversation from signal-mcp's database.' The 'locally stored' qualifier immediately distinguishes it from Signal-side deletions, and the sibling routing makes the boundary explicit.

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?

Explicitly names three alternatives and the condition that selects each: clear_local_store to wipe everything, prune_store to drop by age, delete_message to unsend in Signal. Nothing is left to inference about when to reach for this tool.

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