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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the agent knows this is a safe remote read. Beyond that the description only discloses returned fields and the underlying endpoint (GET /sms/received/{id}), without noting error behavior or access requirements. Adequate with annotations, but not richly informative.

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?

Three tight sentences, front-loaded with the core action and return content, then the sourcing hint, then the endpoint. No filler and every clause 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 single-record read with no output schema, the description covers purpose, parameter provenance, and returned fields, which is nearly everything an agent needs. Minor gaps remain around failure modes and pagination/ID validity, keeping it just shy of a 5.

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%, so the single reply_id parameter is already documented, making the baseline a 3. The description does add provenance ('from notifyre_list_sms_replies'), which is slightly more than the schema offers, but the param's core semantics live in 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 received SMS reply), and enumerates the returned content (text, sender, receiving number). The singular 'one reply' clearly distinguishes it from the sibling notifyre_list_sms_replies, so an agent can separate the two without opening a 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?

Explicitly routes the agent: 'Use the replyID from notifyre_list_sms_replies,' naming the upstream sibling that supplies the required parameter. It gives clear context but stops short of stating when-not-to-use or what happens with an invalid/stale ID.

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