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

Annotations already declare readOnly/idempotent/destructive hints, lowering the bar. The description adds valuable behavioral context: the {results, errors} batch envelope and the provider_incident block with warnings about unreliable limit/balance data. This is beyond what annotations convey and is crucial for safe interpretation of results.

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 tight and well-structured: first sentence states the core function, second covers the parameter, third explains the response envelope, and fourth delivers an important caveat. Every sentence earns its place without redundancy or fluff.

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?

Despite having no output schema, the description covers the return shape, the parameter constraint, and a critical provider-incident edge case. It is complete enough for a single-parameter read-only batch tool, with no major gaps in operational understanding.

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?

With 0% schema description coverage, the description fully compensates for the single parameter. It explains account_ids as an array of IDs, explicitly stating the 1–50 limit, and ties it to the batch operation. This gives the agent complete semantic understanding despite the sparse schema.

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 the tool returns full account objects with extended creditData, per ID via GET /accounts/:id. This specific verb+resource distinguishes it from siblings like list_accounts or get_account_balance, which target summaries or individual data points.

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 usage context: fetch full details for a batch of account IDs (1–50). It does not explicitly mention alternatives or exclusions, but the intent is clear versus list-only or balance-only tools. It could be stronger with a direct comparison, but the batch pattern and data scope imply typical use cases.

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