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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint. Description adds behavioral context about provider_incident block and unreliable values, which is beyond the 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?

Front-loaded with main action and parameter. Could be slightly more concise, but the added detail about provider_incident is important and earned. No wasted sentences.

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 provides complete context: what is returned (full accounts with creditData), how to use (array of IDs), batch shape, and a critical warning. No gaps.

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 only defines type array of strings with 0% description coverage. Description adds crucial meaning: array of 1-50 account IDs, batch shape, and provider_incident warning, fully compensating for lacking schema descriptions.

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?

Clearly states returns full account objects with extended creditData per ID. Distinguishes from sibling tools like openfinance_list_accounts by specifying it provides detailed objects including credit limits.

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 usage: pass account_ids array (1-50) and mentions batch shape. Includes a warning about provider_incident and not presenting values as real. Lacks explicit when-not or alternatives, but context is sufficient.

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