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

Goes well beyond the annotations by disclosing three non-obvious traits: the 64 KiB size ceiling, that the call burns a download quota, and that one-time files are destroyed afterward. The consumption/destruction language is fully consistent with destructiveHint=true and idempotentHint=false.

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?

Four short sentences, front-loaded with what the tool returns and how big it can be, followed by auth, side effects, and the fallback. No filler or repetition of the schema.

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 still specifies the return encoding (base64) and size bound, and it flags the irreversible quota/side-effect behavior. An agent has everything needed to decide whether to call it and what to expect.

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 already 100%, so the baseline is 3; the description earns an extra point by clarifying that accessToken applies only to private files and that workspace access is an acceptable substitute. That conditional framing adds meaning the schema's terse 'when required' does not convey.

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?

States a specific verb+resource ('Download a file'), plus the output encoding and a hard size ceiling (64 KiB as base64). That is enough to distinguish it from inspect_temporary_file and delete_temporary_file, which it never names explicitly, so sibling differentiation is inferred rather than stated.

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?

Gives a concrete when-not clause ('Use HTTP for larger files') and a precondition for private files ('need their access token or workspace access'). It does not route the agent to inspect_temporary_file when it only wants metadata, which would be the obvious sibling alternative.

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