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

Annotations already declare non-destructive, idempotent, non-read-only; the description adds the per-user scoping ('for the authenticated user') and the credential-pin default, which are not in the annotations. It stays silent on error behavior for unknown/unauthorized ledgers, but that is a modest gap given an output schema exists.

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 sentences, the action semantics first and the target-selection detail second. Every clause carries information; nothing is padding.

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?

With annotations covering the safety/idempotency profile and an output schema handling return values, the description only needs to explain intent and the ledger default, which it does. Only edge-case behavior (invalid ledger, missing permission) is left unstated.

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 50% — the boolean 'starred' has no schema description, and the description compensates by defining both values precisely. For 'ledger' it reiterates owner/name and the pin default, mostly matching rather than extending the schema text.

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-and-resource pair ('Set starred ... to star a ledger or unstar it') scoped to 'the authenticated user'. No sibling tool in the list touches starring, and the description makes the two-way toggle explicit.

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?

Explains exactly how to invoke for each intent: starred:true to star, false to unstar, and that ledger selects the target. It doesn't address preconditions (e.g., ledger must exist, permission to star) but no competing alternative exists to route against.

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