Add a contact to Crazytel SMS Center with a phone number. Optionally include display, first, or last name for easier identification.
Create an SMS Center contact. Requires phone_number; optional display_name, first_name, last_name.
| Name | Required | Description | Default |
|---|---|---|---|
| last_name | No | Last name | |
| first_name | No | First name | |
| display_name | No | Display name | |
| phone_number | Yes | Contact phone number |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the full burden of behavioral disclosure, but it only states that this is a create operation and lists required/optional fields. It does not disclose side effects, idempotency, duplicate handling, response behavior, or any postconditions an agent might need to know for a mutating 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?
A single front-loaded sentence with zero filler. It leads with the verb and resource, then covers requirements and optional parameters economically. Every word earns its place.
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?
Adequate for a simple 4-parameter tool with fully documented schema fields, but with no annotations and no output schema, the description omits return-value behavior and any postconditions. An agent invoking a create operation would benefit from knowing what the tool returns, making this minimally complete but not thorough.
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 100%, so the baseline is 3. The description adds marginal value by summarizing which parameter is required and which are optional, but this largely duplicates the schema's 'required' array and property descriptions.
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 states a specific verb and resource — 'Create an SMS Center contact' — which is clear and unambiguous. The 'SMS Center' qualifier helps differentiate it from generic contact operations, though it doesn't explicitly name or contrast any sibling tool, so it falls short of a full 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?
The description gives no guidance on when to use this tool versus alternatives like add_contacts_to_list or update_contact. It only restates parameter requirements ('Requires phone_number; optional...'), which is schema-level information rather than usage context, and provides no exclusions or decision rules.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.