voltage_observe

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

Annotations already convey read-only and closed-world hints. The description adds valuable behavioral context: it clarifies that 'watch' is a closed vocabulary, that the tool runs a single pass, and that missing elements imply guards never fire. This goes beyond the annotations and provides actionable insight into the tool's behavior.

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 concise, with two short paragraphs that are front-loaded with the core purpose. Every sentence adds distinct value—stating the action, vocabulary constraint, and practical implication. There is no fluff 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?

The description captures the tool's primary purpose and a key behavioral consequence, and an output schema exists so return values are already documented. However, it does not explain non-required parameters (region, read_text, max_elements), which are likely needed for correct invocation. This gap reduces completeness, though the core use case is well covered.

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 compensate. It explains 'watch' as the closed vocabulary, which is essential, but it omits any explanation for 'region', 'read_text', and 'max_elements'. With only one parameter addressed, the description fails to adequately clarify the remaining parameters, leaving the agent with insufficient guidance.

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 clearly states a specific verb and resource: 'Run one vision pass and return grounded elements in screen coordinates.' It also explains a distinct use case—checking if the vision model can find elements before committing to a Playbook. While it doesn't explicitly contrast with sibling tools, the purpose is specific and unambiguous.

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 provides explicit context for when to use the tool: 'Use this to check that the vision model can actually find what a state depends on before committing to it in a Playbook.' This is a clear directive without naming alternatives, but it effectively guides the agent on ideal usage scenarios.

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