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

The description discloses several non-obvious behaviors: links are 'short-lived,' return values differ based on path presence, and the URL requires specific HTTP verbs and headers for download/upload. Annotations only indicate non-readonly/non-destructive, so this added context is valuable, though it omits details like exact expiry duration or auth requirements.

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, densely packed with essential conditional logic and HTTP usage details. No filler words, and the core purpose is front-loaded before the conditional specifics.

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 tool with no output schema, the description clearly conveys the two return structures and the exact call patterns for download and upload. However, it leaves the api_token parameter and link expiration duration unspecified, which are relevant for a complete invocation picture.

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 description coverage is 0%, so the description must compensate. It meaningfully explains how 'path' and 'access' affect the returned URL and operations, but does not touch 'workspace_id' or 'api_token.' Workspace_id is inferable, yet api_token's purpose remains unexplained, leaving a partial gap.

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: 'Short-lived direct link to blob storage' and explicitly frames it for 'large or binary files.' It clearly distinguishes this from sibling read/write tools by focusing on link generation rather than content transfer, and it details both path and no-path behaviors.

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 clear context for when to use: 'for large or binary files,' and explains the read vs. readwrite scenarios. It does not explicitly name alternatives like read_file or write_file or state when not to use the tool, so it falls short of a 5.

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