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

Annotations already declare destructiveHint=true and readOnlyHint=false, so the safety profile is known, but the description adds nothing beyond that: it does not say whether stopping is reversible (a resume_contact_campaign sibling suggests it is), whether queued or in-flight messages are cancelled, or what permissions are required. For a destructive mutation with zero added context, this is a significant gap.

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?

A single short sentence with no filler, so nothing is wasted, but it is under-specified rather than concise in any useful sense. There is no front-loaded scoping or consequence statement to anchor the agent.

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 a destructive, non-read-only mutation with no output schema and fully undocumented parameters, so the description carries the full burden and falls well short. An agent cannot determine the effect on the contact's campaign state, reversibility, or parameter mapping from this text.

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 both required parameters (id, campaignId) are undocumented in the schema and the description must compensate. It only weakly implies that the operation is scoped to a contact and a campaign; it never clarifies which parameter is the contact identifier versus the campaign identifier, nor what entity type each refers to.

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?

"Arrêter la campagne pour un contact" states a specific verb (stop) and resource (campaign, scoped to a contact), so the agent can distinguish it from generic campaign tools. It does not differentiate it from the obvious counterpart resume_contact_campaign, which sits in the sibling list. The French phrasing in an otherwise English toolset is a minor inconsistency but the meaning is still unambiguous.

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?

There is no when-to-use guidance: no prerequisites, no note that this is the inverse of resume_contact_campaign, and no exclusion such as when to use cancel_subscription or batch_actions instead. The agent must infer all routing from the name alone.

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