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

Annotations already declare destructiveHint=true, idempotentHint=true and readOnlyHint=false, so safety is partly covered. The description still adds real behavioral value beyond them: the billing consequence of leaving parts in place, the guarantee that existing objects are untouched, and the explicit idempotency semantics ('already gone counts as success'). Auth or permission requirements are not mentioned.

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 dense sentences, each carrying a distinct point (destructive scope, non-interference with objects, idempotency), with the primary action front-loaded. Phrasing is slightly terse and idiomatic but no sentence is filler.

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 destructive, idempotent operation with no output schema, the description covers scope, billing side effects, and idempotency, and annotations carry the safety profile. Return behavior and permission prerequisites are unaddressed, but these are minor for this tool class.

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%, with all four required parameters (connectionId, bucket, key, uploadId) documented in the schema itself. The description adds no parameter-level detail such as formats or the source of uploadId, so the baseline 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 states a specific verb and resource: it discards an upload plus its already-sent parts. It also distinguishes itself from object-deletion siblings by noting it 'cannot touch an object that already exists at the key,' so an agent can tell it apart from delete_object. It stops short of naming siblings such as abort_unfinished_uploads or complete_multipart_upload.

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 scope note ('cannot touch an object that already exists at the key') implicitly tells the agent this is for discarding in-progress uploads rather than deleting objects, which is a weak when-not signal. However, no alternative is named and no explicit condition for choosing this over abort_unfinished_uploads or complete_multipart_upload is given.

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