Open SAP Vault Session

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

Annotations indicate readOnlyHint=false (write operation), openWorldHint=true, etc. The description adds value by noting that session and vault PDAs are visible on-chain metadata and advising on what to store (intentionally encrypted payloads or public hashes). This goes beyond annotations.

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, no unnecessary words. The first sentence states the core purpose; the second adds essential context. Every sentence earns its place.

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 description covers purpose, input, and behavioral context. An output schema exists, so return values are handled. For a vault session opener, the description is sufficiently complete.

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 100%, and the description repeats the parameter format (32-byte session hash as byte array, hex, or base64). It adds no new meaning beyond the schema, meeting the baseline for high coverage.

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 clearly states the action ('Open a vault session') and the input ('by 32-byte session hash'). It distinguishes from sibling tools like sap_fetch_session and sap_session_start by specifying 'vault session' and providing SAP MCP context.

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 context about the SAP MCP memory/session flow and what to store, but does not explicitly state when to use this tool versus alternatives, nor when not to use it. It lacks clear usage guidelines.

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