evidence_bundle

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

With no annotations present, the description carries the full behavioral burden, and it delivers: it discloses a validation pipeline ('folds each Merkle proof against the on-chain Relay root BEFORE including it') and a failure mode ('refuses any fact that fails'). It also clarifies that only finalized attestations are accepted, giving the agent a concrete expectation of 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?

Three sentences, each earning its place: the packaging purpose, the validation behavior, and the intended usage scenario. There is no filler, no repetition of schema details, and the key facts are front-loaded.

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?

The tool has complex, nested input and no output schema, yet the description never states the returned bundle's form or how to pass it to a verifier such as evidence_verify. It also leaves the boundary with fdc_bulk_proof_bundle implicit, so an agent is left to infer when one is preferred over the other.

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 about 80%, so the baseline is 3; the schema already documents most parameters. The description adds useful context by linking network/voting_round_id to Relay-root validation and confirming Web2Json attestations are supported, but it does not clarify whether at least one evidence source is required or explain the optional claim parameter 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?

The description uses a specific verb and resource: 'Package several proof-carrying facts into one portable bundle.' It also names the exact input sources (FTSO Scaling anchor feeds and finalized FDC attestations, including Web2Json) and the Relay-root validation, which separates it clearly from sibling read/verify 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?

There is an explicit use case: 'Use when an agent needs to hand a downstream consumer, an auditor, or another agent the evidence its decision rested on.' It does not, however, state when not to use it or explicitly compare with fdc_bulk_proof_bundle for FDC-only scenarios.

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