check_ledger

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

With no annotations, the description carries the burden, and it does disclose the actual validation rules applied (overlaps, budget breaches, dates, holiday bounds), which is real behavioral content. It does not state side-effect freedom or error/failure behavior, so a small gap remains.

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?

Two tight sentences: the check list first, the call-to-action second. Nothing is redundant or padded.

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 values need not be described, and the check list is informative. But with a nested, undocumented `ledger` object and no annotations, the definition is thin on what input is actually valid.

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 0% and the single `ledger` parameter is a nested, open object, so the description must compensate. "The whole ledger" implies the full document is required, but nothing describes its expected shape or required fields, leaving the agent to guess what to pass.

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 (validate) and resource (the whole ledger), then enumerates exactly what is checked: overlaps, budget breaches, bad dates, out-of-holiday trips. No sibling does validation, so an agent can route here without inspecting other schemas.

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?

"Run this before telling the user a plan works" gives a clear trigger condition tied to the workflow. It stops short of naming alternatives or exclusions (e.g. per-trip checks vs. whole-ledger), so it is strong context rather than full when/when-not guidance.

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