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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds genuine value by enumerating the response fields (recipient, text, sent/done time, parts, price, state, error) and the underlying endpoint, which matters since there is no output schema. It omits behavior on unknown ids or empty results, keeping it from a 5.

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 compact clauses with the resource and lookup key front-loaded; every phrase (including the endpoint) carries information. No filler.

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-parameter read, it covers purpose, the input's origin, the returned fields and the endpoint. Missing only failure-mode behavior for invalid or expired ids, which would complete the picture in the absence of an output schema.

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 single parameter is fully documented in the schema, including that the id comes from emailchef_send_sms. The description only restates "by message id" and adds no format or constraint detail, so baseline 3 applies where the schema does the work.

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+resource with scope: "Delivery status of one sent SMS by message id." This clearly separates it from siblings like emailchef_send_sms and emailchef_get_sms_balance without needing the schema.

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?

Usage is only implied – "one sent SMS" and "by message id" suggest a post-send lookup, but the description never states when to use this versus other SMS or status tools, nor any prerequisites. It stops short of naming conditions or alternatives.

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