Get a signed backup download URL

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

Annotations already indicate readOnlyHint=true, idempotentHint=true, and destructiveHint=false, but the description adds crucial behavioral detail: the URL is short-lived, grants access to anyone holding it, is never written to the audit log, and should be treated as a bearer credential. It also implies the return is a URL, not the archive itself. This goes well beyond annotations and is essential for safe use.

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 two sentences, front-loading the purpose and then delivering critical security context. Every sentence earns its place; there is no filler or repetition. It is compact yet comprehensive.

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?

The tool has an output schema, so return values are covered. The description addresses when to use, security handling, and the ephemeral nature of the URL. It also clarifies that the URL is for a single backup. Nothing essential is missing for an agent to call this tool correctly.

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?

The input schema provides 100% coverage with clear descriptions for both 'server' and 'backup_uuid', including an example and a pointer to ptero_list_servers for valid identifiers. The tool description does not add parameter-specific semantics beyond the schema, but with complete schema coverage, that is acceptable. It receives the baseline score.

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-resource pair: 'get a signed, short-lived URL for downloading one backup archive.' It clearly distinguishes from siblings like ptero_list_backups (which lists backups) and ptero_create_backup (which creates them). No other sibling provides a download URL, so the purpose is unambiguous.

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?

It explicitly says 'Use this when the human wants to pull a backup down outside the panel.' This is a clear condition for use. The description also provides security-oriented instructions (treat as bearer credential, don't store/paste/reuse), which act as usage constraints. Since no sibling offers a similar function, alternatives are not needed.

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