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

Annotations already declare destructiveHint=true, idempotentHint=false, openWorldHint=true, so the safety profile is covered. The description adds nothing beyond that: it doesn't say the original text is overwritten (not versioned), that edits may be time-limited on WhatsApp's side, or what happens on failure.

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?

Five words, front-loaded, zero waste. It is appropriately sized for a short entry, though the terseness tips into under-specification rather than efficient completeness.

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?

A destructive mutation with no output schema needs its description to cover failure modes and edit constraints, and this one covers none. The schema documents the parameters adequately, but an agent still lacks the information to call this correctly in edge cases.

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 100% and all four parameters carry their own descriptions, so the schema does the heavy lifting. The description contributes no additional meaning, such as whether id_message must belong to the same chat_id/instance_id, which is the baseline-3 outcome.

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?

A specific verb (Edit) plus specific resource (a previously sent message) – unambiguous, and implicitly separated from the sibling write tools send_message and delete_message. It stops short of naming those siblings or clarifying what 'edit' means at the WhatsApp level.

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?

No guidance on when to choose edit over send_message or delete_message, no prerequisites, and no mention of the well-known WhatsApp restriction that only your own messages and only within a short window can be edited. The agent must infer all of this.

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