Update an existing contact. Requires write scope.
| Name | Required | Description | Default |
|---|---|---|---|
| No | Email address | ||
| phone | No | Phone number | |
| lastName | No | Last name | |
| contactId | Yes | The contact ID | |
| firstName | No | First name | |
| defaultLocation | No | Default meeting location for this contact |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already indicate readOnlyHint=false and destructiveHint=false, so the write nature is known. The description adds the write scope requirement, which is useful context beyond annotations. However, it does not disclose whether the update is partial (only provided fields) or full replacement, nor what happens if the contact does not exist. With annotations lowering the bar, a 3 is appropriate.
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 a single sentence that efficiently communicates purpose and a prerequisite (write scope). No unnecessary words or repetition, making it appropriately sized and front-loaded.
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 simple update tool with six basic parameters and existing annotations, the description covers the purpose and permission. However, it lacks crucial behavioral details like whether the update is partial (patch) or full (put), and what the response contains. The absence of an output schema and the openWorldHint also leave room for ambiguity, making this minimally viable but not complete.
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 schema covers all six parameters with individual descriptions (100% coverage). The description adds no parameter-specific meaning beyond what the schema already provides, so the baseline of 3 is correct.
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's function ('Update an existing contact') with a specific verb and resource. It distinguishes from sibling tools like create_contact and delete_contact by explicitly indicating modification of an existing record.
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 implies usage for modifying an existing contact and notes the write scope requirement, but it does not explicitly state when to prefer this over alternatives (e.g., create_contact for new contacts) or provide exclusion criteria. The context is clear but lacks explicit guidance.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.
Most tools are clearly distinct, but update_calendar overlaps with specialized tools like update_booking_settings, update_confirmation_settings, and the reminder management tools (add/delete/get reminders). This creates ambiguity about which tool to use for modifying specific settings such as buffers or reminders, though descriptions help clarify the intended scope.
All 28 tools follow a consistent verb_noun snake_case pattern (e.g., create_calendar, get_appointments, update_contact). The verbs are predictable (add, cancel, create, delete, get, reschedule, send, update), making the API easy to navigate.
With 28 tools, the set exceeds the 25+ threshold typically considered too many. While each tool serves a legitimate purpose, the high number is overwhelming and likely includes more granularity than necessary; some settings tools could be consolidated.
The tool surface covers the full lifecycle of calendars, appointments, and contacts, including availability, overrides, reminders, confirmation settings, and notifications. There are no obvious dead ends or missing operations; cancellation and rescheduling handle appointment changes, and send_invitation covers creation.
