Hvac add air handler

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

Annotations already declare the mutation profile (readOnlyHint=false, idempotentHint=false, destructiveHint=false), so the description is not required to re-establish that this writes data. It adds one real piece of context — the fan node must already exist — but says nothing about the effect of the non-idempotent flag (e.g., that repeated calls create additional handlers) or what the call returns.

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 sentence carrying the verb, resource, and attachment point, with no filler or repetition of the title. Appropriately sized for a low-complexity add operation.

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?

With no output schema, the description should ideally say what a successful call yields (e.g., the created air handler id/handle), and it does not. Annotations plus the fully documented schema cover parameters and safety, so the definition is callable, but the return contract and failure behavior remain unaddressed.

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%: nodeId, fanType, maxAirflowCFM and staticPressurePa are all documented in-schema including defaults. The description's only contribution is clarifying that nodeId refers to a fan node, which the schema already states ('Fan node ID'), so baseline 3 is appropriate.

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 pairs a specific verb ('Add') with a specific resource ('air handler unit (AHU)') and scopes the target ('to an existing fan node'), which clearly separates it from hvac_add_node, hvac_add_duct, or hvac_update_air_handler. It stops short of explicitly naming a sibling to distinguish itself from, which is the only thing keeping it out of the top band.

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 phrase 'to an existing fan node' implies the prerequisite that a fan node must already exist before calling this, which is genuinely useful usage context. However, there is no statement of when to choose this over hvac_update_air_handler, no note on whether duplicate air handlers per node are permitted, and no exclusion conditions.

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