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

Annotations already declare destructiveHint=true, openWorldHint=true and readOnlyHint=false, so the agent knows this is an irreversible outward-facing action. The description adds meaningful context beyond that — the consent requirement and the Twilio dependency — but omits whether it sends one message or fans out to a campaign, and says nothing about cost, rate limits, or failure behavior.

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?

Two short sentences, front-loaded with the action and followed by the prerequisite. Nothing is wasted, though the extreme brevity is part of why key semantics are missing rather than a sign of disciplined economy.

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?

This is an irreversible, open-world send with an undocumented identifier and no output schema, so the description carries a heavy burden. It covers prerequisites but not the target of 'id', the scope of the send, or what the caller gets back — insufficient for a destructive tool of this shape.

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% and the single required parameter is a bare 'id'. The description never clarifies whether this id refers to a contact, a conversation, a campaign, or a queued message — the most consequential ambiguity for a destructive send tool. The one thing the description should have disambiguated is left entirely undocumented.

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?

The description names a specific verb and resource ('Lancer l'envoi réel de SMS'), and the qualifier 'réel' signals a live send rather than a draft or preview. It implicitly distinguishes itself from the messaging siblings (send_whatsapp, send_telegram, send_newsletter) by channel, though it never names them explicitly.

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?

'aux contacts consentants' and 'Twilio requis' establish two real preconditions (recipient consent, Twilio configured) that an agent must satisfy before calling. However, there is no explicit guidance on when to choose SMS over send_whatsapp/send_telegram, and no statement of what should not be done (e.g. no bulk blasting, no unconsented contacts beyond the adjective).

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