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

Annotations already declare readOnly, idempotent and non-destructive, so the safety profile is covered; the description goes further by disclosing cost/account posture ('Free, read-only, no account'), an input legality constraint ('inputs must be public and non-personal'), and an explicit scope disclaimer about fault/cause/liability. It does not describe the timeline's structure or handling of unverified receipts.

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?

Three dense sentences: trigger, inputs, output plus disclaimers. Front-loaded with the usage condition and nothing repeated unnecessarily.

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 no output schema, the description usefully characterizes the return (verified source-attributed timeline plus an Art. 73 reference aid) and covers the key input restrictions. Remaining gaps are minor: it doesn't state behavior when only ai_system_ref is supplied (the schema does) or how verification failures surface in the result.

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 schema already documents all five parameters including the enum on source_type and the data_classification constraint. The description restates receipt_ids and observations and echoes the public/non-personal requirement without adding syntax, format, or edge-case meaning beyond the schema.

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?

Specific verb and resource: it takes receipt_ids plus observations and returns a verified, source-attributed timeline. It also states a precise non-outcome ('No fault, cause or liability finding'), which tells an agent exactly what kind of artifact this produces versus the sibling receipt-verification tools.

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 this when something went wrong with an agent and you need the facts in order' gives a clear triggering condition. It does not name alternatives (e.g. gaip_evidence_pack, gaip_receipt_export) or state when not to use it, so routing between the similar bundle/pack siblings is left to inference.

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