Fetch SAP Subscription

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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false. The description reinforces this by stating 'Read-only SAP SDK wrapper' and 'inspect current chain state', adding practical context. No contradictions and no new negative traits disclosed.

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-loaded with the core action, and no unnecessary words. It efficiently communicates purpose and usage context without 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?

The description adequately covers the tool's behavior (two fetch modes, read-only nature, and when to use). The presence of an output schema reduces the need to describe return values. However, it could mention that it fetches a single subscription, but overall it is sufficient for an agent to understand and invoke 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?

Schema description coverage is 100%, with each parameter already explained in the input schema. The description only summarizes the two fetch modes ('by PDA or by agent PDA/subscriber/subId') without adding new semantics or clarifying interaction beyond what the schema provides.

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 'Fetch a subscription by PDA or by agent PDA/subscriber/subId', specifying both the verb 'fetch' and the resource 'subscription'. It also distinguishes two distinct lookup modes, which helps differentiate it from sibling tools like sap_fetch_attestation or sap_fetch_escrow.

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 provides clear context: 'Use these reads to inspect current chain state before mutating...' This gives a strong hint about when to use the tool (before mutations). However, it does not explicitly mention when not to use it or compare with other fetch tools, but the intent is clear.

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