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

Annotations already declare this is a destructive, non-idempotent, open-world write. The description adds meaningful policy context beyond them: the reply must be text-only and attachments are blocked by MCP policy. It does not explain what the destructive effect looks like to the ticket recipient, but the extra constraint is useful.

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?

Three short sentences, front-loaded with the action and followed by the two relevant constraints. No filler or redundant fields.

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?

Given the output schema and rich annotations, the description covers the essential policy constraints an agent needs before calling. It could clarify that the reply becomes visible to the ticket requester, but nothing critical is missing.

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%, so the input schema already documents all three parameters, including the confirmation semantics. The description only restates the confirmed=true requirement and says the message is text-only, adding little beyond the schema.

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 and resource: 'Replies to a support ticket.' This clearly distinguishes a reply action from create/get/list support-ticket siblings by verb, but it does not explicitly name an alternative or clarify boundaries with hgr_create_support_ticket or hgr_post_helpcentre_contact.

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?

The description gives a prerequisite ('Requires confirmed=true') and a constraint (text only, no attachments), which implies when to use it. It does not say when to prefer hgr_create_support_ticket or hgr_post_helpcentre_contact, nor when not to reply.

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