slack_files_complete_upload_external

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

Annotations (readOnlyHint=false, destructiveHint=true, idempotentHint=true, openWorldHint=true) already carry the safety profile. The description adds some context about governed-connector routing and effect verification ('Spring verifies it', 'approval_ref... when resuming a write'), which is useful. However, it says nothing about the actual state change the operation performs on Slack, what gets finalized, or consequences of completing the upload. The description does not contradict the annotations.

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 description is well-structured: an identity line, a routing constraint, then a clean bulleted Args list covering all 7 parameters. There is no fluff or redundancy, and each sentence carries information. It is appropriately sized for the parameter count, though more content would have been justified given the tool's complexity.

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 7-parameter governed connector tool with 0% schema coverage, this is under-specified. It omits what the Slack operation does, what the `arguments` JSON should contain, the prerequisite relationship with `slack_files_get_upload_url_external`, and what the output represents (despite an output schema existing). An agent could not reliably construct a correct call to this tool from the description alone.

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?

With 0% schema coverage, the description's Args list is the only documentation, and it adds genuine meaning for the infrastructure parameters: project_id is an authenticated UUID, connector_account_ref is a project-bound alias, idempotency_key is a stable business identity, approval_ref is for resuming writes. However, the central parameter `arguments`, which carries the actual Slack operation payload, is described only as 'JSON string of arguments for the connector operation' — a tautology that leaves the agent with no idea what fields the Slack files.completeUploadExternal payload requires.

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 'Slack connector operation `files_complete_upload_external`', which merely restates the tool's name without explaining what the operation actually accomplishes. It never states that this finalizes/commits a Slack external file upload, what it returns, or how it relates to the file upload lifecycle. The only substantive claim is about routing authority, which is infrastructure context, not purpose.

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?

No guidance is given on when to call this tool versus alternatives. Critically, the sibling list contains `slack_files_get_upload_url_external`, which is the natural prerequisite for this operation, yet the description never mentions this pairing or any required sequence. There are no exclusions, preconditions, or alternative-tool references anywhere.

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