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

The annotations already establish that this is a non-read-only, non-destructive, non-idempotent, closed-world mutation. The description adds useful context by requiring a source and stating the effect: the value is recorded with its date and source.

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?

The description is appropriately sized and front-loads the purpose and source requirement. The opening sentence is awkwardly ordered and harder to parse than necessary, but no material filler is present.

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 five-parameter mutation with full schema coverage, annotations, and no output schema, the description covers purpose, exclusions, source requirements, amount convention, and effects. It does not explain append-versus-overwrite behavior for repeated records, though the non-idempotent annotation signals that.

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. The description adds meaning beyond the schema by explaining the asset-versus-loan positive-amount convention and emphasizing that the figure must come from an external source, not an estimate.

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?

The description identifies the action as stating/recording what an asset is worth or what is owed on a loan, with source attribution. It distinguishes this from statement-based balances, though the phrasing is convoluted and does not name a sibling alternative directly.

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?

It gives clear exclusions: never estimate values, and bank/card balances come from statements rather than this tool. It does not explicitly name the sibling tool to use for those statement-based balances, leaving that routing slightly implicit.

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