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

Beyond the readOnlyHint: false annotation, the description adds a useful behavioral constraint: only unsent scheduled texts can be canceled. However, it does not mention what happens if the text has already been sent, whether cancellation is reversible, or any permission requirements, so some burden remains uncovered.

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 sentences with no filler; the action and condition are front-loaded, and the parameter source is provided efficiently.

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 one-parameter cancellation operation, the description covers the operation, the condition, and the source of the identifier. It does not describe the response or error behavior, but no output schema exists and the operation is simple enough that this is a minor gap.

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% and the schema describes task_id as 'The scheduled text to cancel,' which is the baseline. The description adds important provenance for the value: it comes from the scheduling response or from list_scheduled_texts, going 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?

States the exact operation: canceling a text that was scheduled via send_text_to_user and has not been sent. This clearly differentiates it from other text-related tools like send_text_to_user and list_scheduled_texts.

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?

Tells the agent when it applies (scheduled, not yet sent) and exactly where to obtain the required task_id: from the scheduling response or list_scheduled_texts. It does not explicitly rule out alternatives, but its scope is specific enough that no close alternative exists among the siblings.

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