Download an accessible SAS original

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

Adds substantial behavior beyond the annotations: the write target (configured private local directory), the non-destructive filename policy ('new random filename; never overwrites'), provenance metadata (SHA-256 plus catalog/book/chapter/source), and a revalidation step for ancestry and own-class visibility. These are consistent with readOnlyHint=false, destructiveHint=false, and idempotentHint=false, and they tell the agent what side effects to expect on disk.

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?

Front-loaded with the core action and destination, then layered with provenance, filename behavior, and constraints; every clause carries information. The telegraphic, jargon-dense style ('Revalidates resource ancestry and own-class visibility') makes it slightly harder to parse than a clean 5.

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 three fully documented parameters, present annotations, and an output schema (so return values need not be explained), the description covers destination, naming, provenance, and validation. Minor gaps remain around what makes a resource 'accessible' and what happens on a failed visibility check, but nothing an agent needs to invoke it correctly is missing.

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 100% and all three parameters already carry descriptions tying them to earlier SAS catalog/section tools, so the baseline is 3. The description reinforces this with 'No caller URL, header or filename is accepted,' but adds no per-parameter meaning beyond the schema.

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 and object: save an unencrypted original official PDF for a given resource into a configured local directory. That is unmistakably distinct from every sibling, which are all read-only catalog/search/list tools. The scope ('official', 'unencrypted', 'original') is precise enough that an agent knows exactly what artifact it gets.

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?

Provides a real conditional exclusion: 'Protected books use the official portal reader,' which tells the agent when this tool will not deliver. It also constrains inputs with 'No caller URL, header or filename is accepted,' steering the agent to supply only IDs. It stops short of explicitly naming the prerequisite call sequence (e.g. get IDs from sas_get_material/sas_list_resources), so not quite a 5.

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