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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds one genuinely useful behavioral fact — that a completed job returns an absolute, temporary download URL, meaning the URL expires — but says nothing about polling behavior, failure states, or how long the URL stays valid.

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?

Two short sentences with no filler, and the core action is front-loaded. It is arguably under-specified rather than overwritten, but nothing is wasted.

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?

An output schema exists, so return values need no explanation here. However, for a status-polling tool with a required identifier and zero schema documentation, the description should at minimum say where job_id is obtained and whether repeated calls are expected.

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%, so the lone parameter job_id is documented nowhere except by its type. The description does not explain where a job_id comes from (presumably returned by convert_image_url) or what form it takes, leaving the agent to infer the entire parameter contract.

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?

States a specific verb and resource: check the status of an XLS.now conversion job. It is distinguishable from convert_image_url (which starts a conversion) and from list_converters / get_api_usage, though the description never names those siblings explicitly to reinforce the distinction.

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?

Usage is only implied — 'Check a XLS.now conversion job' suggests it follows a conversion submission, but there is no explicit when-to-use statement, no polling cadence guidance, and no mention of what to do while a job is pending versus after it completes.

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