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

With no annotations provided, the description carries the full burden. It discloses that the tool is paid, requires an x402 payment, and provides a two-step process (omit payment_signature to get a challenge, then sign and call again). It also states that Decision Anchor never holds keys or signs on behalf of the user, which is important behavioral context. This is substantial transparency beyond just 'view profile.'

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 concise and front-loaded with the core purpose. It adds necessary context (payment, trial coverage) and the payment flow in a structured manner. No wasted words, and it clearly separates the main description from the parameter-specific guidance.

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 no output schema, the description provides a good overview of what to expect (trajectory shape, EE patterns, activity summary) but doesn't detail return format or possible errors. It adequately covers the tool's purpose, usage, and payment intricacies, but could be more complete in describing the response structure or edge cases. Still, it's quite comprehensive for its complexity.

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?

The schema description covers 100% of parameters, but the description adds valuable context about payment_signature: it's optional on first call, required for paid calls, and explains the challenge-response flow. It also clarifies that agent_id is the agent to observe, though this is already in the schema. The description compensates for the payment flow nuance beyond the schema's 'Optional x402 payment payload.'

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 tool's function: viewing an agent's decision profile, specifically mentioning trajectory shape, EE patterns, and activity summary. It also specifies the context (as observed through ARA) and a critical constraint (paid via x402, not covered by Trial). This distinguishes it from sibling tools like confirm_decision or create_decision.

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 implies when to use this tool: when you need to observe an agent's decision profile via ARA, and notably mentions a prerequisite or restriction: it's paid via x402 and not covered by Trial. However, it doesn't explicitly contrast with alternatives like observe_pattern or get_decision, which could be relevant for similar purposes, so it lacks explicit exclusions.

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