ads_wait_until

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

Goes well beyond the readOnly/destructive annotations by disclosing the blocking nature, the notification-driven fast path, the polling fallback at interval_ms, the meaning of met_at_plc_ms, and the returned fields. This is exactly the behavioral context an agent needs for a long-running blocking call.

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?

The blocking behavior is front-loaded and the fallback/timestamp details are packed into one dense but readable passage with no filler. The parenthetical heavy structure is slightly harder to scan than ideal, but nothing is wasted.

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?

With an output schema present, the description is not obliged to detail return values, yet it still names them briefly. It covers mechanism, fallback, and timeout, and only omits prerequisites such as whether a connection (ads_connect) must exist first.

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 0%, so the description must carry the load, and it does so only partially: it enumerates the legal comparison operators for 'op' and explains interval_ms as the polling cadence when notifications are unavailable. It never explains what 'name' expects (symbol path form) or what types 'value' accepts, leaving two of five parameters undefined.

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 gives a specific verb (Block/waits until) plus the resource and the exact predicate form ('symbol <op> value'), and the blocking semantics cleanly distinguish it from non-blocking siblings like ads_read, ads_watch, and test_expect.

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 implied rather than stated: an agent can infer you call this to wait for a PLC condition and that a timeout bounds the wait. There is no explicit when-not guidance and no mention of alternatives such as ads_watch (non-blocking observation) or test_expect for assertions.

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