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

Annotations already establish the safe read-only, non-destructive, closed-world profile, and the description adds real behavioral detail beyond them: what the calendar actually returns (decision spans from recorded day to expectation deadline, plus standalone dated items) and the roughly one-year window limit. Pagination and result volume are not addressed, so not a 5.

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 entryId-vs-from/to decision, then the return semantics, then the filtering use case and the exclusion. Dense but nearly every clause earns its place; the single long paragraph is slightly harder to scan than bulleted alternatives.

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 read-only list tool with a fully documented schema and annotations covering safety, the description supplies the missing pieces: the two call modes, the window constraint, the returned item types, and the anti-use case. No output schema exists, so return-shape detail here is a bonus rather than a 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 coverage is 100%, so the baseline is 3, but the description adds meaning the schema lacks: entryId scopes to one decision's plan, from/to must be paired and kept to about a year, and ownerUserId is framed by its use case. Only `tag` goes unexplained beyond the schema.

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 read operation on the ledger plan/calendar and defines its two modes (per-decision via entryId vs. calendar window via from/to) in the first sentence. It is clearly distinguishable from siblings ledger_plan_add/update/delete, which mutate the same resource.

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 routes the caller: pass entryId for one decision, from+to for the calendar, and use ownerUserId for 'what's mine this week' or 'tomorrow's items to draft'. It also states a when-not — never use it to compare or rank people's output — so both selection and exclusion are covered.

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