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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety and external-data expectations are provided. The description adds useful behavioral detail about what the returned object contains (every recipient, statuses, parts, cost) and the underlying API path. However, it does not disclose rate limits, pagination, or error behavior for missing ids.

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 efficient sentences. The result content is front-loaded, followed by the id source, then the API endpoint. Every sentence earns its place.

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 one-param read tool with annotations covering safety and open-world behavior, the description is nearly complete. It covers what is returned and where the id comes from. Missing only peripheral error/absent-id behavior.

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 schema's message_id description already distinguishes the SMS message id from the friendly id. The description points to sources for the id but adds no format, syntax, or validation meaning 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 a specific verb (Get) and resource (one sent SMS message) and enumerates what the result includes: recipient status, delivery status, message parts, cost. This distinguishes it from notifyre_list_sent_sms and notifyre_get_sms_recipient.

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?

Explicitly says where to get the id: notifyre_list_sent_sms or notifyre_send_sms. That is clear routing context, but it does not name what the tool should not be used for (e.g., getting a single recipient rather than the whole message).

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