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

Annotations only give the generic profile (readOnlyHint=false, openWorldHint=true, destructiveHint=false); the description adds genuinely non-obvious behavior — confirmation-link gating before alerts activate, a private ntfy subscribe link, paid-plan/U.S.-only SMS, consent gating, and rate limits (one digest per daily check, at most one text a day). Nothing here contradicts the annotations.

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?

Dense and front-loaded — the channel-selection premise comes first, then each action in a logical add/verify/remove order. It is a single semicolon-chained sentence, which is slightly run-on, but nearly every clause carries distinct, load-bearing information.

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?

Covers the full action lifecycle (get/add/remove/verify), consent requirements, delivery cadence, and privacy constraints despite no output schema. The only small gap is that 'get shows the current setup' does not hint at the returned shape, though with no output schema that is acceptable.

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 carry the load; it documents the action enum's meaning per value, explains that consent must be true only after user agreement, and ties 'code' to the verify_sms step. It adds little about email/phone formats (the schema's email pattern and phone maxLength already cover those), so a 4 rather than a 5.

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?

Opens with a specific verb+resource framing ('Choose where alerts go besides this chat') and enumerates every action with its distinct effect, so the agent can tell add_email/add_phone/add_sms apart and distinguish this channel-management tool from the sibling alert/watchlist tools.

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 per-action conditions: add_email requires the user to confirm via link before alerts start, add_phone is for the free ntfy app, add_sms is limited to paid plans and U.S. numbers, consent:true only after the user agreed, verify_sms with the code, and remove_* to stop. It also states the alternative implicitly (this chat vs. other channels) and a hard privacy precondition for adding addresses.

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