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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the description does not need to re-establish safety — yet it adds genuinely new context by labeling the Landauer term 'established physics' and the Intelligence Bound a 'working conjecture', which tells the agent how much to trust the output. 'Free' and 'deterministic' also go beyond the annotation labels. It stops short of describing error behavior for nonsensical inputs (e.g. non-positive power).

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 core statement is front-loaded in the first sentence, with the return contents following in a single dense but readable sentence. 'Free, read-only and deterministic' partially duplicates the annotations, the one piece of wording that does not fully earn 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?

This is a stateless pure computation with a rich output schema, so the description only needs to convey inputs and trust level — which it largely does, including the epistemic caveat on the conjecture. The missing bandwidth parameter meaning and default temperature are the only real gaps.

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 carries the full burden. It effectively explains power_w (via 'power budget'), temperature_k (via k_B*T), and measured_bits_per_s (via 'if you pass a measured rate'), but bandwidth_bits_per_s is never connected to the rho*B term, and neither units nor the 300 K default are mentioned. Helpful but incomplete compensation.

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 names a specific subject — a thermodynamic ceiling on information processing for a power budget — and enumerates exactly what comes back (Landauer ceiling, the min(rho*B, P/(k_B*T*ln 2)) bound, which term binds, and optional shortfall). The computing verb lives in the title rather than the description, and no sibling overlaps this domain, so there is nothing to disambiguate.

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 only implied: an agent can infer this is for reasoning about power-limited compute ceilings, and the clause 'if you pass a measured rate' hints at an optional comparison mode. There is no explicit when-to-use statement, no when-not-to-use, and no reference to any alternative tool in the sibling set.

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