Plan a change to a ChurchTools appointment

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

Beyond the annotations, it discloses genuinely useful traits: no partial update is supported, so the plan resends the whole current appointment, the preview lists changed fields, and series edits apply to all occurrences. The 'writes nothing' phrasing sits in mild tension with readOnlyHint=false, but that hint is conservative and the destructiveHint=false value is consistent.

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 sentences, no waste, and the most decision-relevant fact ('Writes nothing') is front-loaded before the mechanics of full replacement and series scope.

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 no output schema, the description usefully explains what the plan preview contains (changed fields) and how it applies to series. The notable remaining gap is that it never tells the agent how to carry the plan forward (the execute-plan sibling), which matters for a two-phase mutation tool.

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 already 86%, so the schema carries most parameter meaning. The description nevertheless adds a material parameter insight: because there is no partial update, the caller must supply the whole appointment rather than a sparse diff, which changes how every field is populated.

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 names a specific verb and resource ('returns a plan that changes the stored appointment') and immediately distinguishes the tool from writable siblings by stating 'Writes nothing.' It also clarifies the non-obvious scope that 'for a series the change applies to every occurrence,' so an agent can separate it from ct_delete_appointment or a plain read tool.

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 gives clear context for when the tool is used (as the planning stage of an appointment change, not a direct write) and notes the full-replacement constraint that shapes the call. It does not, however, name the follow-up sibling (ct_execute_plan) needed to actually apply the plan, so the workflow routing is left implicit.

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