Plan a change to a ChurchTools event

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

With annotations already declaring destructiveHint=false and openWorldHint=true, the description still adds real behavioral context: it writes nothing, it returns a plan rather than a mutated resource, and only changed fields are transmitted. There is a mild tension with readOnlyHint=false, but the statement is a deliberate clarification of a plan/apply pattern rather than a false claim about the operation; it stops short of explaining how the plan is consumed.

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 critical fact ('Writes nothing') is front-loaded, and the single dense sentence contains no filler. The semicolon-chained clauses are information-packed but slightly heavy for the amount of content.

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 four-parameter plan tool with no output schema, the description covers what is mutated and what is not, but leaves the agent without any sense of the plan object's shape or the required follow-up step (executing the plan via the sibling ct_execute_plan). Adequate but with a clear gap for a tool whose whole purpose is producing an artifact.

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 100%, so the schema already documents all four parameters and the baseline would be 3. The description adds meaning beyond it by enumerating the three mutable fields (canceled, note, admins) and by stating the diff semantics that only changed fields are sent, which directly shapes how the agent should populate the 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?

States a specific action and resource: returns a plan that changes an event's cancel state, note, or admins. It also bounds the field scope explicitly ('ChurchTools takes no other event field here'). It does not differentiate from siblings such as ct_execute_plan or ct_delete_event, so it falls short of a 5.

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 by the name and by the negative boundary statement that no other event field is accepted here, which steers the agent away from unsupported updates. However, there is no explicit when-to-use, no mention that the returned plan must subsequently be run through ct_execute_plan, and no comparison against ct_update_appointment or ct_delete_event.

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