rec_latency

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

Annotations already declare readOnlyHint=true and destructiveHint=false. The description adds substantial behavioral context beyond annotations: it defines the measured interval as from the first condition becoming true to the next condition becoming true and specifies PLC timestamps. It does not describe pair limits or no-match behavior, but the core computation is well disclosed.

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 sentences, front-loaded with the core computation and followed by a compact example. No wasted wording, and the example directly clarifies the parameter syntax.

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?

The core latency logic is clear, and the output schema means return values need not be described. However, the description omits when to use this tool versus recording siblings, does not mention `id` or `max_pairs`, and does not state prerequisites such as an existing recording. These gaps make it only adequately complete at 0% schema description coverage.

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 burden. It explains the `symbol op value` structure for six required condition parameters and gives an example for `==` and `>`. It does not explain `id` or `max_pairs`, but it compensates well for most parameters.

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 computation (edge-to-edge latency between two PLC conditions) and gives a concrete example. An agent can distinguish it from raw recording tools, but the description does not explicitly differentiate it from siblings such as rec_pulses or rec_compare.

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?

Provides no when-to-use guidance, no alternatives, and no prerequisites such as requiring an active recording. Usage is only implied by 'in a recording,' leaving the agent to infer the appropriate scenario.

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