tascan_get_sms_status

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

Annotations already cover the safety profile (readOnlyHint=true, idempotentHint=true, destructiveHint=false), so the description's job is to add context beyond them. It does: it discloses the exact status values the agent should expect (queued/sent/delivered/undelivered/failed) and the presence of carrier error codes, which helps an agent interpret results. This is non-redundant, useful behavioral information consistent with the annotations.

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 tight sentences with zero filler. The first sentence front-loads the action and key selection criterion; the second enumerates the return states. Every clause earns its place, including the parenthetical that ties the SID to its source tool.

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?

This is a simple single-parameter read-only lookup with 100% schema coverage and full annotations. The description covers what the tool does, how to identify the target message, what outcomes to expect, and that carrier error codes accompany failures. Nothing an agent needs to invoke it correctly is missing; an output schema is not required to explain a flat status list.

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% — the schema already documents twilio_sid as 'Twilio message SID (SM...) from tascan_send_sms'. The description reinforces that same provenance but adds no new semantic detail beyond what the schema provides, so the baseline 3 applies.

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 opens with a specific verb and resource ('Check delivery status of a previously sent TaScan SMS'), then narrows the scope by identifying the exact lookup key (Twilio SID) and its source (tascan_send_sms). This makes it immediately distinguishable from the only plausible sibling, tascan_send_sms, without any 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 establishes clear usage context: this tool is for checking status after sending, and the SID it requires comes specifically from tascan_send_sms. It names the producing sibling, which effectively routes the agent to use this tool only after a send. It stops short of explicitly stating when not to use it or naming competing alternatives, but the pairing with tascan_send_sms makes the intended workflow clear.

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