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

Beyond the annotations, the description adds important behavior: it returns an exact preview and a five-minute confirmation token, requires confirmation, validates that posting accounts belong to the current chart, and explicitly does not apply the change. These details materially help the agent understand the two-step workflow and safety constraints.

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 three tightly written sentences with no waste. The core purpose and non-application constraint are front-loaded, and each subsequent sentence adds useful context.

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 preview mutation with no output schema, the description explains the key return values (exact preview and five-minute token) and the confirmation requirement. It could go further by explaining how the token is used, but the essential context is present.

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?

The description only broadly mentions currency and posting-account defaults, plus a chart constraint. The schema has several undocumented fields such as clear_gl, clear_currency, default_gl_provider, default_gl_account_id, and client_id, with 0% schema description coverage, so the description does not compensate for the missing parameter semantics.

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 names a specific verb and resource: preparing an update to a client's currency and posting-account defaults. It also clearly distinguishes this preview tool from an actual applying change by stating it 'does not apply the change.'

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 description provides clear context for using the preview: it requires confirmation and returns a five-minute confirmation token. However, it does not explicitly name the non-preview sibling update_client_defaults or state when not to use this tool.

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