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

With no annotations, the description carries the full burden and does contribute real behavior: auth scheme, daily free quota, per-page pricing, and that it returns job_id. It omits failure modes, whether the image is persisted, max page/upload size, and idempotency behavior for retries.

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?

Telegraphic but front-loaded and efficient: upload, auth, pricing, return value, in that order, with no filler. Slightly clipped phrasing ('base64', 'then €0.01/page') trades a little readability for density.

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?

There is no output schema, so 'Returns job_id' is a useful, necessary disclosure, and pricing/auth context is present. But for a four-parameter job-submission tool it leaves three parameters and the downstream polling step undocumented, which is a meaningful gap 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 description coverage is 0% across four parameters, and the description explains only image_base64. mime, tcg_type, and idempotency_key get no meaning, defaults, or accepted values from either source, leaving the agent to guess how to control the scan type or safely retry.

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 states a concrete verb and resource: upload one binder photo as base64 to start a scan job, returning job_id. That clearly contrasts with get_scan_job and purchase_credits, though it never names the sibling used to poll results, so the agent must infer the workflow.

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 signals an account requirement (Bearer mgt_ token, 3 free pages/day, then €0.01/page), which hints at when the tool is usable and points business logic toward get_free_key/purchase_credits. It never explicitly says 'call this first, then poll get_scan_job', so the usage path is only implied.

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