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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior, so the safety profile is covered. The description adds a genuine behavioral instruction beyond that: terminate polling when all sessions are terminal, which tells the agent how to manage loop lifetime. It does not describe the returned session shape, leaving a small gap.

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?

A single compact sentence with the scoping qualifier ('unfinished') front-loaded and the polling guidance second. Nothing is wasted, though the phrasing is terse enough that it borders on under-specification.

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 and the description does not indicate what a session record contains or how 'terminal state' is represented in the response. For a zero-parameter polling tool this is a meaningful gap, though the core invocation semantics are adequate.

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?

The tool takes zero parameters, so there is no parameter meaning to convey and the baseline of 4 applies. The description correctly adds no redundant parameter prose.

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 ('Read unfinished uploads'), which narrows the scope to non-terminal sessions and distinguishes it from a general listing. However, it does not explicitly contrast itself with siblings like list_uploads or get_upload_session, leaving the boundary to inference.

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 clause 'stop polling once all uploads reach a terminal state' implies the intended polling workflow and when to cease calling, which is useful context. It gives no explicit when-to-use-vs-alternatives guidance, such as when to prefer get_upload_session for a single upload.

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