provenance

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

No annotations are present, so the description carries the full burden. It explicitly says 'Read-only', reveals that it checks whether the current value still matches the write receipt ('a later relabel is loud'), and states that the returned `limits` honestly declare what the tool does NOT prove. This is strong disclosure of behavior and limitations, though it omits error/edge-case behavior.

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 long but every clause adds information: purpose, output constituents, usage, and limitations. It is front-loaded with the central question and avoids repeating schema details. The all-caps and dash-heavy style is somewhat dense, but nothing is redundant.

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's enumeration of what the answer contains (source, lineage, grade, limits, etc.) partially substitutes for one. It covers read-only safety and honest limitations. Minor missing details: parameter combination behavior, error handling, and the exact shape of `limits`.

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?

The schema provides no parameter descriptions (0% coverage), but the description adds essential meaning: `key` identifies the fact across all its values, while `id` selects one record. It does not clarify whether both can be passed, precedence, or behavior when neither is provided, but it significantly compensates for the schema gap.

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 opens with a precise question ('WHERE DID THIS FACT COME FROM') and enumerates exactly what the tool assembles: source, lineage, origin attestation, evidence grade, value history, policy retirement, and write-receipt match. It clearly differentiates this from siblings by covering 'the whole record' and by noting what it does not prove.

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 explains the calling convention (pass `key` or `id`) and states the read-only nature, but it does not explicitly say when to choose this tool over alternatives like `history`, `verify_claim`, or `check_sources`, and it gives no exclusion conditions. Usage context is implied by the purpose rather than directly stated.

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