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

Annotations indicate read-only and idempotent. Description adds critical behavioral context: provider_incident block when Open Finance provider has an open incident, causing unreliable credit limits/balances. This goes beyond annotations.

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?

Description is succinct, front-loaded with main purpose, no wasted words. Three sentences cover purpose, usage, and critical edge case efficiently.

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 single-parameter tool with no output schema, the description covers all essential aspects: what is returned (full objects, batch shape), the key parameter constraint, and the important provider incident warning. Sufficient for correct invocation.

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 has 0% description coverage, so description carries full burden. It adds the array range (1–50) and explains how the parameter is used, including the batch shape and provider incident behavior.

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 clearly states it returns full account objects with extended creditData per ID, specifies the HTTP method and path, and distinguishes from sibling tools like list_accounts by focusing on per-id detail with batch shape.

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?

Specifies to pass account_ids as an array (1–50) and explains batch shape. Implicitly suggests usage when extended creditData is needed, but lacks explicit when-not or alternative recommendations.

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