engineering.exponential_reliability

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

Annotations already cover read-only, deterministic-style behavior (readOnlyHint, idempotentHint, openWorldHint=false), and the description adds real domain context: λ must be >0, t ≥0, unit consistency requirement, and 30-significant-digit precision. It does not discuss pagination/format concerns (none apply) nor error behavior for invalid inputs beyond the stated bounds.

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-loaded with the formulas, then constraints, then the sibling alternative, then a precision note. Every sentence carries information an agent needs; nothing is redundant with the schema or annotations.

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 return-value explanation is unnecessary, and the description still names the outputs (R, 1−R, MTBF). With only two parameters, units and domain assumptions documented, and an explicit alternative named, the definition is essentially complete; only the string-typed numeric inputs go unremarked.

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% — both properties are bare strings titled 'Time' and 'Failure Rate'. The description compensates by defining λ as failures per unit time with >0 constraint and t as time in the same unit. It leaves unexplained why both are typed as strings (presumably arbitrary precision), which is the only remaining ambiguity.

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?

Names the specific model and the exact quantities computed: reliability R(t)=exp(−λt), unreliability 1−R, and MTBF=1/λ. An agent can distinguish it from probability.exponential_cdf/pdf and from engineering.weibull_reliability without opening any schema.

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 states the validity domain (constant failure rate / random-failure regime) and routes wear-out cases to weibull_reliability. It also gives the precondition that λ and t must share the same time unit, with the consequence of getting it wrong spelled out.

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