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

Annotations already mark it read-only/idempotent, and the description adds behavioral context beyond that: default is one instant status check, wait:true blocks until completion or budget expiry, and results may carry llmContext guidance to follow. This meaningfully informs agent expectations for polling and continuation.

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?

Three sentences with no filler: the first states what it does, the second mandates when not to call it, the third explains the wait modes and result guidance. Every sentence carries operational value and the most critical info appears first.

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?

With a full output schema present, the description correctly focuses on invocation context rather than return fields. It covers the prerequisite (request_file_upload), the correct timing relative to the user message, wait semantics, and how to handle llmContext — everything an agent needs to call it correctly.

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 100% and the description repeats rather than extends the wait parameter's meaning ('true = block until the user completes...'). It adds no new parameter semantics beyond what the schema already provides, so the baseline of 3 applies.

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 names a specific verb ('Check'), the exact resource ('an upload link created by request_file_upload'), and the result ('uploaded file ids (files group)'). This clearly distinguishes it from siblings like request_file_upload (which creates the link) and get_file (which fetches an existing file).

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 explicitly states when to call ('on the user's message after they were shown the link'), includes a hard exclusion ('never in the same turn that shared it'), and explains the wait/default behavior and retry pattern ('call again to keep waiting'). This gives the agent a precise invocation rule.

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