Start an upload session, reserving storage quota (editor/admin on the project).

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

Annotations already indicate non-readOnly and non-destructive nature. The description adds 'reserving storage quota', which is a behavioral trait beyond annotations. However, it does not disclose session lifecycle, quota limits, or error states, so only moderate added value.

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 a single sentence, which is efficient in word count but lacks structure. For a tool with many parameters and a multi-step process, it could be more informative while remaining concise. It earns a middle score for brevity without substance.

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?

Given the tool's complexity (9 parameters, part of an upload workflow with missing output schema context), the description is insufficient. It does not mention return values (likely a session ID) or next steps, leaving the agent without complete guidance.

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 9 parameters and 0% schema description coverage, the description fails to explain any parameter meanings. Terms like asset_key, file_count, is_categorical, target_collection_id, target_item_id, total_bytes, transfer_method are left undefined, leaving the agent without guidance.

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?

Tautological: description restates name/title.

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 description mentions 'editor/admin on the project' as a prerequisite but provides no guidance on when to use this tool versus alternatives (e.g., when to choose this over uploads.signed_url). No explicit when-to-use or when-not-to-use advice.

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