lookup_register

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

With no annotations, the description carries the full behavioral burden. It usefully discloses the returned fields (meaning, unit, range, matching pump menu parameter, hardware confirmation) and input representations, but it does not explicitly state that this is a read-only operation, nor does it mention error behavior for invalid registers.

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 two sentences with no filler. It front-loads the tool's scope and immediately follows with accepted formats and return contents, so every sentence earns its place.

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 the description need not fully specify return structure, but it still gives a useful return overview. For a simple lookup tool this is nearly complete, with the main gap being the undocumented 'lang' parameter and no sibling-routing guidance.

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 adds strong meaning for the required 'register' parameter by explaining that 'r32', '0x32', and '32' are accepted hex forms, but it entirely omits the optional 'lang' parameter.

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 states a specific verb and resource: looking up one EXT-bus register in the ThermIQ map. It gives the accepted input formats and domain context, making the purpose clear, though it does not explicitly distinguish itself from siblings such as lookup_terminal or search_kb.

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?

Usage is implied by the narrow 'one register' scope and the accepted format examples. However, there is no explicit when-to-use guidance, no when-not guidance, and no named alternative for related tasks like searching the knowledge base or looking up terminals.

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