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

Annotations already declare readOnlyHint=false, destructiveHint=false, idempotentHint=false, so the safety profile is covered. The description adds genuinely non-derived context: the return payload (signed_url + storage path), which target tool to call next, and the required 'upload_urls:write' scope. It stops short of stating URL expiry, single-use behavior, or size constraints, keeping it from a 5.

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?

Front-loaded with purpose and return values before the longer routing list, which is the part an agent most needs to get right. The six numbered cases are justified by the genuine branching logic, though the list is verbose enough that it slightly exceeds the ideal length.

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 no output schema, the description must explain return values, and it does (signed_url to PUT to, plus the storage path to persist). Combined with the bucket-to-tool routing and the scope requirement, an agent has everything needed to call this tool and correctly chain the follow-up write.

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 coverage is 100%, so baseline is 3, but the description meaningfully enriches the bucket parameter by associating each enum value with a concrete use case and downstream tool (e.g., 'attachments' for work order/request/PM attachments), which the schema only partially captures. It adds little for file_name beyond the schema's own max/min bounds.

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 first sentence states a specific verb+resource ('Generate a signed upload URL for uploading a file to AssetLab storage') and immediately names the outputs (signed_url and storage path). It is unambiguous about what the tool does and how it differs from all the create_* siblings that consume the resulting URL.

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 provides an explicit routing table mapping each file type to the correct bucket and the follow-up tool (update_asset, create_asset_document, update_work_order, create_attachment, create_project_document, create_contract_document). It also states an exclusion/ambiguity rule ('always ask the user which type they mean if ambiguous'), which is exactly the when-to-use guidance this tool needs.

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