waver_value_at

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

Beyond the readOnlyHint annotation, the description discloses important behavioral details: it returns the last change at or before the time, accepts human-readable or tick times, and handles past-end time by returning the last recorded value with a flag. These boundary behaviors are genuinely useful and not inferable from the schema. No contradiction with 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 opens with a clarifying question, then packs key usage details, parameter semantics, edge-case behavior, and the sibling alternative into a compact block. Every sentence adds information; there is no filler or redundancy.

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 read-only point-query tool with an output schema and readOnlyHint, the description covers the core semantics, time formats, edge-case behavior, and the relevant alternative. Nothing essential for selecting and invoking the tool is missing, and the output schema handles return-value details.

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?

With 0% schema description coverage, the description compensates by explaining 'time' in detail (human-readable vs integer file ticks) and clarifying that 'signals' supports multiple signals in one call. The 'file' parameter is not elaborated, but its meaning as the waveform file is reasonably inferable from the tool family context. Significant value added over the bare schema.

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 precise question form ('what was <signal> at 10ns?') and states the exact resource and behavior: returning the value held at that instant. It also differentiates itself from waver_values by explicitly saying waver_values covers a whole window of changes. This is a specific, non-tautological definition.

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?

It clearly identifies when to use this tool ('Answers what was <signal> at time X') and explicitly directs to waver_values for a whole window of changes, naming the alternative. Batch usage is also explained. This gives an agent actionable selection guidance beyond the tool name.

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