Dial digit

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

Annotations already declare readOnlyHint=false, idempotentHint=false, openWorldHint=true, so the write/non-idempotent profile is covered. The description adds nothing beyond the endpoint path — no statement about the active call requirement, whether the call_id must reference a live call, or what happens if the call is gone.

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?

It is short, but only because it says almost nothing; the one added sentence is a raw HTTP route that an agent calling an MCP tool rarely needs. This is under-specification rather than disciplined concision.

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?

A CTI mutation with four required parameters and no output schema needs to explain the live-call precondition and the effect of dialing a digit; none of that is present. The annotations cover only the generic write profile, leaving the operational context missing.

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 100%, so all five parameters (including the response_format enum) are already documented in the schema. The description contributes nothing extra, which lands at the baseline of 3 for fully-covered schemas.

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 restates the tool name and title verbatim ("Dial digit") and appends only the raw HTTP route. It does not clarify what a 'digit' means in this CTI context or how it differs from the near-identical sibling placetel_cti_send_dtmf_digits.

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?

No when-to-use guidance at all. With siblings like placetel_cti_dial, placetel_cti_send_dtmf_digits, placetel_cti_start_transfer, and placetel_cti_answer in the same CTI family, the agent gets no signal about which one to pick for which in-call action.

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