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

Annotations already declare destructiveHint=true and idempotentHint=true, so the description's job is lighter, and it does add genuine consequence detail: cancelling a scheduled message prevents it from being sent. That is the key behavioral fact an agent needs before calling a destructive tool. It stops short of saying whether a cancellation is reversible or whether DONE can be undone.

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 outcome, no filler. The key destructive consequence is the last thing read, which is good placement.

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?

With no output schema, the description should say what a successful call returns or what happens if the reminder is already in the target state. For a destructive, idempotent mutation with a partially documented schema, that leaves the agent guessing about the result and about error conditions.

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 only 33%, so the description needs to compensate. It partially does: it defines what DONE and CANCELLED mean semantically, which the bare enum does not, and the parenthetical 'de whatsapp_list reminders' hints at where reminder_id comes from. However reminder_id itself remains undescribed and brand_id's handling is covered only by the schema, so the gap is narrowed but not closed.

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 pair (marcar como hecho / cancelar) applied to a specific resource (elemento de la agenda de WhatsApp), and anchors it to the sibling list tool 'whatsapp_list reminders'. It is distinguishable from whatsapp_add_reminder and whatsapp_schedule_message, 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?

Usage is implied rather than stated: an agent can infer it should be called when the user wants to close out or cancel an existing reminder. There is no explicit 'when not to use', no mention of consulting whatsapp_list first, and no alternative for rescheduling (which would presumably be add/cancel + re-add).

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