Partial-update an appointment

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

With no annotations, the description fully discloses the PUT semantics and fetch-and-merge behavior, preemptively warning users about Cozi's full replacement approach. It also details how to toggle all-day. It could be improved by mentioning error conditions or authorization needs, but the core behavior is transparent.

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 description is extremely concise—two sentences that are front-loaded with the purpose. Every sentence adds value; there is no fluff or repetition.

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 complexity (10 parameters, no output schema, no annotations), the description does not fully cover all necessary context. It explains the merge behavior and all-day toggle but omits details on error handling, prerequisites (like how to obtain appointment_id), and the response format. It is adequate for a simple use case but lacks completeness for a robust 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 description coverage is 0%, so the description must compensate. It only explains the 'all_day' parameter and related 'start'/'end', but provides no guidance on other optional parameters like 'subject', 'attendees', 'notes', 'location'. The required parameters are implicitly explained (fetch from year/month page), but many parameters remain undocumented.

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 clearly states the tool performs a partial update on an appointment, distinguishing it from create_appointment and delete_appointment by explaining its unique merge behavior. The verb 'Partial-update' and resource 'appointment' are specific.

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 explains when to use this tool (to update an appointment) and provides guidance on switching between timed and all-day appointments. However, it does not explicitly state when not to use it or contrast it with alternatives like create_appointment for new items.

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