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

The key behavioral fact an agent needs is stated explicitly: this returns a guide and "opens nothing by itself." That matches readOnlyHint/idempotentHint/openWorldHint=false and adds meaning the annotations cannot convey (that the actual action happens through a separate browser tool). It stops short of describing the guide's shape beyond a parenthetical and says nothing about limits or failure modes.

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?

The first two sentences earn their place and are front-loaded correctly. The final sentence about Zendesk's REST/Support API and the absence of a hosted MCP server is background rationale rather than call-time guidance, and the date stamp ("checked 16 Oct 2026") is noise for an 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?

With zero parameters and no output schema, the description does the necessary work by stating what is returned ("screens, buttons, fields") and clarifying that execution happens through cotlet_browser_* tools. Only the handoff specifics (which browser tool to start with, or what the guide assumes about the current page) are left unstated.

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?

The tool takes no parameters, so the baseline is 4. Since there is nothing for the schema to explain, the description would only need to note the absence of inputs, which the empty schema already signals.

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 the verb and resource ("Reply to ticket in the user's own Zendesk account") and immediately corrects the obvious misreading by saying it returns step-by-step instructions rather than performing the reply. It does not explicitly contrast with zendesk_update_ticket or zendesk_add_internal_note, so siblings remain partly ambiguous.

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?

Gives a clear follow-on path ("then do it with the cotlet_browser_* tools in the user's Zendesk Cloud Browser"), which is real usage guidance. However, it never says when to call this instead of zendesk_update_ticket or zendesk_add_internal_note, which are the most confusable siblings for replying on a ticket.

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