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

Annotations already declare destructiveHint=true and idempotentHint=true, so the description's real contribution is 'Calls already placed are not undone' — a precise disclosure of partial irreversibility that the annotations cannot express. It stops short of stating error behavior for finished broadcasts or any permission requirements.

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?

Two short sentences, zero waste, with the scope constraint front-loaded and the irreversible-effect caveat second. Nothing to trim.

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 single-parameter destructive tool with full annotation coverage and no output schema, the description covers what gets destroyed and what does not. A minor gap remains around the outcome when the target broadcast is already finished or the ID is invalid.

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% and the single 'id' parameter is documented with a UUID pattern, so the schema carries the burden. The description adds no format or lookup guidance beyond what the schema provides, making the baseline 3 appropriate.

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?

States a specific verb (cancel) plus resource (call broadcast) and narrows scope to 'outgoing or scheduled ... that has not finished.' The call-vs-text split against the sibling dialmycalls_cancel_text is unambiguous from the resource name alone.

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?

'That has not finished' implies the applicable state, but the description never routes the agent to alternatives (e.g., dialmycalls_cancel_text for text broadcasts) or states what to do when the broadcast is already complete. Usage is inferable rather than explicit.

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