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

Goes well beyond the annotations: it explains the real-world consequence (subscribed relays, motors, lights, locks act on the value), states the action is irreversible from here, and discloses concrete rate limits (30/min free, 60/min Plus). These are exactly the behavioral facts an agent needs and that destructiveHint/openWorldHint cannot convey.

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?

Front-loads 'WRITE:' so the operation class is visible at a glance, then packs consequences, consent constraint, rate limits, and endpoint into a few tight sentences. Every sentence carries load-bearing information.

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 5-param write tool with no output schema, the description covers consequences, irreversibility, rate limits, and consent. It omits any mention of authentication/permission requirements and what the call returns on success, which is a minor residual gap.

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 lat/lon/ele/value/feed_key are already fully documented in the schema and the description adds no per-parameter syntax or formatting guidance. Baseline 3 applies since the schema does the heavy lifting.

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?

States a specific verb ('publish'), the exact resource ('one data point (a value) to a feed'), and even the underlying endpoint POST /feeds/{feed_key}/data. It is trivially distinguishable from read-side siblings like adafruitio_get_data_point and adafruitio_list_feed_data.

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?

Explicitly constrains when to use it ('Only publish a value the user has asked for') and frames it as the write counterpart to the many read-only siblings. It does not name a competing tool, but no sibling writes a data point, so the routing risk is low.

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