Open evidence

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

Annotations already declare readOnlyHint and openWorldHint, so safety is covered. The description adds genuine behavioral context beyond that: what fields the returned receipt contains (claims, source URL, timing precision, when HEY knew, backing) and that withdrawn records are explicitly flagged.

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 motivating question is front-loaded and the payload description is dense but single-pass. The long inline prefix list is necessary information but makes the single sentence heavy; a small structural break would help without losing content.

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?

For a one-parameter read tool with a full output schema and readOnly/openWorld annotations, the description covers purpose, valid input types, returned fields, and the withdrawn-record edge case. An agent has everything needed to call and interpret it.

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% and the schema already shows the id pattern, so baseline is 3. The description goes further by enumerating the valid typed prefixes (ship:, signal:, abi:, claim:, etc.), which the schema's generic pattern does not convey.

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 ('Open the record') and resource (a typed evidence id cited by a HEY answer), then enumerates the exact id prefixes accepted. An agent can distinguish it from siblings like explain_fact or get_contract 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?

The opening question 'What backs this claim?' gives a clear trigger condition for use, and the receipt framing implies verification/provenance workflows. It does not name an alternative tool or state when not to use it, so it stops short of full routing guidance.

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