list_scheduled_messages

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

With no annotations, the description carries the behavioral burden. It discloses that the tool returns scheduled jobs by default (pending only) and enumerates the returned fields. This gives an agent a concrete sense of the tool's read-only, listing behavior and output shape.

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 concise sentences carry all essential information: what the tool does, what it returns, and where to go for cancellation. The most important part is front-loaded and there is no redundancy.

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 simple list tool with one optional parameter and no output schema, the description is largely complete: it states the default scope (pending), the return fields, and the related cancellation tool. The behavior of include_done is left to the schema, which fully explains it, so nothing critical is 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?

The schema already describes the only parameter (include_done) with 100% coverage. The description does not need to repeat it, so the baseline of 3 is appropriate; no additional parameter meaning is added 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 clearly states the verb and resource: 'List pending scheduled messages,' and adds the returned fields (ID, recipient, send time, status). This distinguishes it from sibling tools like cancel_scheduled_message and run_scheduled_messages without ambiguity.

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 implies the tool is for viewing pending scheduled messages and explicitly routes cancellation to cancel_scheduled_message. It does not explicitly contrast with schedule_message or run_scheduled_messages, but the use case is clear enough for an agent to decide when listing is appropriate.

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