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

Annotations are all false, so the description carries the full behavioral burden. It discloses the return behavior (structured summary only, never PDS text), the fallback path (inbox when no policy matches), the size limit, the storage/parse path parity, and the required permission. This is rich, actionable transparency.

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 compact and front-loaded with the core purpose. Every sentence adds a distinct operational fact: input format, storage parity, linking fallback, return type, size cap, and permission. There is no filler or repetition.

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 write tool with no annotations and no output schema, the description covers the essential call-time concerns: required permission, size limit, input encoding, fallback behavior, and return type. The only notable gap is the exact shape/content of the structured summary, but the description makes clear that PDS text is not returned.

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%, so the baseline is 3. The description adds value beyond the schema by stating the max decoded size, clarifying the accepted base64/data URL format, and tying policy_id behavior to automatic matching. It does not mention the blob alias or mime_type default, but the schema already covers those.

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 opens with a specific verb and resource: 'File a policy PDF into the vault.' It clearly conveys what the tool does and adds useful scope limits like max size and summary-only output. However, it does not explicitly distinguish itself from the closely named sibling add_policy, so an agent must infer the difference.

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 clear operational context: use it for policy PDFs, send content_base64, respect the 4MB limit, and require vault.write. But it never explicitly says when not to use it or which sibling to prefer instead, so the usage guidance is implied rather than direct.

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