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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the low bar is met. The description adds real context beyond that: the tool is free, and the response includes cryptographic verification of signature, body hash and chain link — telling the agent the result is self-verifying. It does not say what a verification failure returns, which keeps it from a 5.

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 the identity and cost (FREE) and outcome, then the content list, then a one-line usage clause. The return-value enumeration is long but justified because no output schema exists; only minor tightening is possible.

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?

There is no output schema, so the description carries the burden of describing the return payload — and it does so thoroughly (hashes, payer, rail, tx, upstream calls, signature, chain link, verification). With one fully documented parameter and complete annotations, nothing an agent needs to call it correctly is missing.

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% for the single receipt_id parameter, including a pattern and the "rcpt_…" format note, so the schema does all semantic work. The description adds no format or sourcing detail beyond restating "receipt" concepts, which is the baseline-3 case.

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?

States a specific verb and resource (returns a run receipt by id) and enumerates its contents — script sha256, payer, rail, payment tx, upstream calls, signature, chain link. An agent can distinguish this read/verify tool from omnigate_runtime_execute and omnigate_runtime_search without opening a schema.

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?

"Use it to prove what an agent ran and paid for" gives a clear, concrete use case that maps to an audit/proof workflow. It stops short of naming alternatives (e.g., use omnigate_runtime_search to find a receipt_id first) or stating failure conditions, so no explicit when-not guidance.

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