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

Annotations already indicate read-only, open-world, idempotent, and non-destructive behavior. The description adds the critical trait 'deterministic' and emphasizes the need for sanitized inputs, which is behavioral context beyond the annotations. It does not contradict annotations; rather, it reinforces them.

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: the first is a crisp definition, the second is a focused list of forbidden inputs. Every word earns its place, and the most critical information is front-loaded.

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?

With an output schema present, detailed annotations, and a clear description, the tool is well-contextualized. The security constraints are thoroughly covered, and the purpose is unambiguous. A minor gap is the lack of explicit sibling differentiation, but the tool's unique role is still evident.

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%, so the parameters are well-documented. The tool description adds a global constraint about not submitting raw sensitive data, which applies across all parameters. However, it does not add parameter-specific meaning beyond what the schema already provides, so it stays at the baseline.

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: 'Generate a deterministic trust receipt from sanitized request/policy/result/payment summaries.' It uses a specific verb ('generate'), names the resource ('trust receipt'), and specifies the inputs. This distinguishes it from sibling tools like boundary_guard_check or probe_x402_paid_path, which serve different purposes.

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 usage by requiring 'sanitized' inputs and explicitly listing what must not be submitted (auth headers, cookies, API keys, etc.). However, it does not explicitly state when to use this tool instead of siblings or provide exclusions or alternative tool references. The 'Do not submit...' list is a strict input constraint but not a full usage guideline.

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