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

Annotations cover the safety profile (readOnly=false, destructive=false), so the bar is lower, yet the description still adds real behavioral value: the URL is one-time, the transfer is a PUT, and MCP itself never fetches files from the Internet (the caller supplies the bytes). It omits URL expiry and any permission constraints, hence not 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?

Two sentences, zero waste, and front-loaded with the primary outcome (one-time URL + file_id) before the flow detail. The final clause about MCP not fetching files disambiguates an easily misunderstood transfer model in a single short clause.

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, so the description must convey returns, and it does name both the URL and file_id. It also defines the upload method, which an agent would otherwise have to guess. Missing details such as URL lifetime or size limits keep it from a 5.

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 only 50%, so the description must carry the remaining explanatory burden, but it adds no parameter meaning at all. It never touches order_id, access_token, document_type, filename, mime, or size_bytes, leaving the agent to rely entirely on partially documented structured fields.

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 returns a one-time upload URL (PUT) plus a file_id. It also names the sibling add_property_document as the follow-up step, so the agent can place it in the workflow. Differentiation is present but implicit rather than an explicit contrast.

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 lays out the sequence clearly: get the URL here, upload the bytes via PUT, then attach via add_property_document. That gives strong context for when to call it. It does not, however, state any exclusions or prerequisites, so it stops short of full when/when-not guidance.

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