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

With no annotations at all, the description carries the disclosure burden and does a decent job: it enumerates the status lifecycle, names resultUrl as the aggregated download link, identifies errorMsg on failure, and states that terminal tasks are retained for 72 hours — a genuinely useful constraint. It stops short of covering auth needs, polling cadence, or what happens after the 72-hour window.

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 purpose is front-loaded in the first clause, then status semantics are listed compactly with no filler. Slightly dense parenthetical notation, but every clause carries information.

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 status-polling tool with an output schema present, the description supplies the decision-relevant context (state meanings, progress fields, retention window) and need not re-document return values. The main gap is the provenance/format of task_no.

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% for the single required parameter task_no, so the description must compensate — but it says nothing about the identifier's format, where it comes from, or whether it is the value returned by submit_document_task. The status/resultUrl detail it does provide describes outputs, which an output schema already covers.

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 opens with a specific verb and resource (查询 ... PDF 文档识别任务状态), which is clearly distinct from the sibling task-status tools (get_speech_task, get_transcription_task) by media type. An agent can identify which task family this belongs to without opening the schema.

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 implicitly defines the polling workflow by explaining what each status means and what to inspect (doneUnits/totalUnits for progress), which tells an agent how to use the result. However, it never states when to call this vs. alternatives, nor any prerequisite such as needing a task_no from submit_document_task, and no exclusions are given.

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