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

Annotations already mark this as read-only, idempotent, and non-destructive. The description adds genuinely useful behavioral context beyond that: the file bytes never pass through the tool, the returned URL is used to POST to yourself, and the existing connection credential is reused. It also clarifies the server keeps no active-vault state, which is important for correct invocation.

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 three focused sentences with no filler. The core purpose is front-loaded, followed by the key behavioral nuance (bytes do not pass through the tool), and ends with concrete usage timing. Every sentence earns its place.

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 presence of an output schema, full parameter coverage, and annotations describing safety, the description is complete for an agent to decide when to call and what to expect. It covers the endpoint/limits, credential behavior, file types, and the correct call-before-upload workflow.

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?

There is only one optional parameter, and the schema description already covers it thoroughly, including when to include vault_id, what values are accepted, and how to resolve an unresolvable name. With 100% schema description coverage, the tool description does not need to add parameter details; the baseline of 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 ('Get') and resource ('attachment upload target') and explains exactly what is returned: the endpoint and account limits. It also clarifies scope by listing supported file types, which differentiates it from the sibling tools like move_attachment and the note/folder operations.

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 gives explicit temporal guidance: 'Call before uploading to learn the size cap and which file types the plan allows.' It does not explicitly name alternatives or exclusion conditions, but the instruction clearly identifies when this tool is relevant among the sibling set.

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