inspect_rtc_snapshot

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

Annotations already cover readOnly/openWorld/destructive, so the bar is lower. The description adds genuine context with "no PLC access" (the operation never touches live hardware) and marks R4135 as optional. It does not say what happens when values fail validation or how partial maps are treated.

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?

One short clause-pair, front-loaded with the verb and the register scope, with no filler. Density is its strength, but the terseness borders on under-specification rather than true economy.

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?

An output schema exists, so return values need no explanation, and annotations cover safety. What is missing is the validation rule itself (what makes a supplied R4128..R4134 value acceptable) and what the optional packed R4135 must look like, which for a 'validate' tool is the core information an agent needs.

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 coverage is 0% and the single parameter is a free-form map of integer keys, so the description carries the load — and it does specify the expected key range R4128..R4134 plus the optional packed R4135. That is meaningful compensation, though "packed" and the value ranges each register accepts remain unexplained.

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 ("Validate") plus a resource ("R4128..R4134 values ... packed R4135"), and no sibling carries the 'rtc' domain, so it is de facto distinguishable. However the resource is expressed in opaque register jargon with no gloss (RTC = real-time clock? what is 'packed'?), so an agent without domain priors cannot confidently tell what is being validated.

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?

"no PLC access" implies an offline/static validation context, but there is no explicit when-to-use, when-not-to-use, or named alternative among siblings such as validate_ladder or inspect_ldr. The agent must infer that this applies only to snapshot register maps.

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