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

Annotations already declare readOnly, idempotent, not destructive, so the bar is lower. The description adds useful context: 'deterministic,' 'pre-action receipt,' and 'no external action is executed,' which clarifies the tool's side-effect-free and audit-focused behavior. It does not contradict annotations and adds value beyond 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?

Two sentences with no fluff. The first sentence states purpose and inputs; the second gives usage timing and reassurance about safety. Every word earns its place and the key 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?

Given the presence of an output schema, full schema coverage, and robust annotations, the description is complete enough. It explains what the tool does, when to use it, what inputs are expected, and that no external action occurs. No critical gaps remain for an agent to use it 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 coverage is 100%, so the baseline is 3. The description goes slightly beyond by enumerating the core inputs ('request, policy, and optional result evidence'), which maps to three of the four parameters and helps the agent understand their roles. It omits 'nextStep' but the schema covers that.

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 uses a specific verb+resource: 'Create a deterministic, read-only pre-action receipt' and clearly scopes it to 'from request, policy, and optional result evidence.' It distinguishes itself from sibling tools by emphasizing it is a pre-action audit receipt with no external action, which separates it from launch packs and resource probes.

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?

It explicitly states when to use: 'Use before an agent posts, spends, lists, or writes so the decision can be audited.' It also clarifies a key exclusion ('no external action is executed'). However, it does not explicitly name alternative tools or when not to use it, so it stops short of a 5.

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