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

With no annotations, the description carries the full burden and does substantial work: it explains that dependency-free steps run in parallel, that retries are all executed in the worst case, and that backoff waits are counted. It never explicitly states this is a pure, side-effect-free computation with no external calls, which is the main remaining gap.

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 the question, then the mechanics, then the return values — a natural decision-first ordering. Despite the density every clause carries information; nothing is repeated from the schema verbatim without adding interpretation.

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?

No output schema exists, and the description correctly fills that gap by enumerating the three verdicts (pass/unknown/fail) and the returned slack and critical path. Minor omissions remain: it does not say what happens when worstMs is less than expectedMs or otherwise invalid input, nor that durations are in milliseconds.

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 coverage is 67%, and the description compensates by explaining how the fields interact — expected vs. worst-case durations per step, dependencies meaning parallel execution, retries with backoff inflating the worst case, and the remaining time as the budget. The optional overheadMs is not mentioned, which is the one uncovered 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?

Opens with the exact question the tool answers ("Can this plan of steps finish inside the remaining time, in the expected case and the worst case?") and then names the specific inputs and computation (critical path in both cases). An agent can distinguish this from a generic deadline helper without opening the 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?

The framing question makes the intended use case unambiguous: feasibility checking of a step plan against a hard deadline. There are no explicit exclusions or named alternatives, so it stops short of the top score, but no inference is needed to know when to reach for it.

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