update_carrier_subscriber

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

With no annotations, the description fully discloses the guarded-write behavior: read-before, no-op when fields match, confirm flag, write kill-switch, read-after. It also notes the testing limitation and clarifies the None/omit semantics, which is critical for an MCP wrapper.

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 dense but well-organized: it leads with the operation, then lists behavioral constraints, then parameter details. Every sentence earns its place, including the NOTE that clarifies a common pitfall. 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?

For a complex guarded update with 10 parameters and no annotations, the description covers the operation flow, parameter roles, validation constraints, and confirmation requirement. The presence of an output schema means return-value details are not needed. The description is sufficiently complete for an agent to call the tool correctly.

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 explain parameters. It does: subscriber_id sourced from list_carrier_subscribers, confirm must be true, optional fields listed, key_label semantics explained. It also highlights the 1-32 char constraint on subscriber_number, adding value beyond the schema.

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 opens with a clear verb and resource: 'Update a Carrier / ISP Fabric subscriber (PATCH .../subscribers/{id})'. This unambiguously states the operation and target, and the resource name distinguishes it from sibling tools like create_carrier_subscriber or suspend_carrier_subscriber.

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 provides clear usage context: it is a guarded write, requires confirm=true, and mandates at least one provided field. It does not explicitly state when NOT to use it or name alternative tools, but the update semantics and prerequisites are well conveyed.

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