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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, and the description is consistent with them while adding real value: it discloses that no external side effect occurs ('opens nothing by itself') and that the return payload is procedural guidance in the form of screens, buttons and fields. What is missing is whether that guidance is tailored to the user's specific plan/service or is generic, which matters for a zero-parameter tool.

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 operative content is front-loaded and efficient, but the trailing sentence about Planning Center's REST API, its August 2026 MCP server and its read-only status is background trivia that does not help an agent decide to call this tool or how. It inflates the description and dilutes the two facts that matter: no side effects, then use the browser tools.

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?

For a zero-parameter, no-output-schema tool, the description covers what is returned (step-by-step screens/buttons/fields), what does not happen (nothing is opened), and the follow-up tool family needed to actually complete the task. Only the tailoring/scope of the returned instructions is left open, which is a minor gap at this complexity level.

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 and schema coverage is 100%, so there is nothing for the description to disambiguate. Baseline applies; the description correctly implies a context-free, no-argument call.

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?

The description makes clear that despite the verb 'send' in the name, the tool does not send anything: it 'Returns how to do it in Planning Center step by step (screens, buttons, fields) and opens nothing by itself.' That is a specific and useful clarification of what the tool actually does. It stops short of a crisp one-line statement of purpose ('get step-by-step instructions for sending scheduling emails'), so it is clear rather than exemplary.

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?

It explicitly chains the tool to the correct execution path: 'then do it with the cotlet_browser_* tools in the user's Planning Center Cloud Browser.' This tells the agent both the sequencing and the family of tools to use for the real action. It does not, however, distinguish this tool from the other planning_center_* domain tools in the sibling list (e.g. accept_or_decline_a_schedule_request), so the when-not guidance is incomplete.

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