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

Despite minimal annotations, description adds rich behavioral context: FIFO order, local offline, free, execution guidance on pricing, routing, and signer boundary. Discloses state mutation (marks consumed).

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 core function, then usage, then execution guidance. Some redundancy with execution guidance appearing in both description and schema, but efficient overall.

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?

Covers key aspects: what it does, when to use, execution details. Output schema may cover return format. Missing edge case handling (e.g., empty stream), but adequate for a simple consume tool.

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 baseline 3. Description does not add parameter-specific guidance beyond what schema provides, so no extra value.

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?

Clearly states the tool returns unconsumed stream events in FIFO order and marks them consumed, distinguishing it from sibling sap_premium_stream_poll by specifying 'use this instead for local offline access.'

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?

Explicitly says when to use (local offline access) and mentions no x402 charge, providing clear context. Lacks explicit when-not-to-use but differentiates from alternative.

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