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

Annotations set readOnlyHint=false, consistent with the write nature of issuing a receipt. The description adds valuable behavioral context: the receipt is signed by a separate party, offline-verifiable, and includes trust_pubkey verification. It also warns that SaSame does not witness the action, preventing misinterpretation.

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 three sentences, front-loaded with the core purpose, and every sentence adds unique value. No superfluous text. Efficient and clear.

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?

Despite no output schema, the description explains the receipt structure (signed_by, signature, canonical_json) and verification method. Parameter descriptions are complete. The tool's trust model and limitations are clearly communicated. Everything an agent needs to invoke it correctly is present.

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?

All three parameters have schema descriptions (100% coverage). The description adds meaning beyond the schema by explaining the receipt output format (signed_by, signature, canonical_json) and the role of payload ('Optional structured detail to bind into the receipt (hashed; capped in size/depth)') and agent_id ('Self-claimed id of the acting agent (unverified label)'). This enriches parameter understanding.

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 purpose: 'Get an ed25519 receipt for an action/tool-call you (or a peer) report.' It specifies the verb (get), resource (receipt), and details what it does (signs with SaSame's key). Among siblings, it stands out from receipt_state, receipt_status_set, etc., as the only one issuing signed receipts.

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 explicit usage context: 'Use for audit trails, dispute evidence, and recording that a step was reported.' It also clarifies limitations: 'SaSame signs what is reported; it does not independently witness that the action occurred.' While it doesn't list alternative tools, the context is sufficient for an agent to decide when to use it.

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