scope_measure

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds valuable behavioral details beyond annotations: the default reuse of the last capture, the fact that 'fresh' triggers a new capture, and the return envelope structure. These are meaningful operational traits not present in 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?

The description is compact, front-loaded, and well-structured with a purpose statement, default-behavior note, return format, and examples. Every section earns its place, and the examples are concise without redundant prose.

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 tool with four parameters, one required, and a moderate enum, the description provides enough context: it explains the core behavior, the fresh-capture exception, and the return format. It does not describe every possible operation in prose, but the schema covers the enum and parameter constraints, so no critical selection or invocation detail is missing.

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 baseline is 3. The description goes beyond the schema by illustrating realistic invocation patterns and clarifying that sample_rate_hz is relevant to a 'fresh' capture. It does not explain every enum value, but the schema and examples together provide sufficient meaning.

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 uses a specific verb ('Measure') with a clear resource ('voltage and timing parameters from captured waveforms'), immediately distinguishing it from sibling tools like scope_capture and scope_trigger. The operation names in the schema reinforce the intended purpose without 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 clearly states the default behavior ('Uses the last capture by default') and the fresh-capture alternative, giving an agent context on when to use this tool versus performing a capture first. It does not explicitly name alternatives or exclusions, but the usage context is unambiguous enough for correct selection.

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