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 real behavioral context beyond that: source-only observation yields an evidence gap, never a completion verdict, which tells the agent how the tool reports partial states.

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?

A single dense sentence, but front-loaded with inputs before the action and the evidence-gap caveat. Every clause carries information; no filler.

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?

No output schema exists, so the description must hint at results, and it does by describing verification/reconciliation outcomes and the evidence-gap reporting behavior. For a 3-param cross-chain observation tool this is nearly sufficient, with only return-format detail 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 0%, so the description must carry the parameter burden and largely does: it explains the signed preflight artifact, the Base depositForBurn hash (source_transaction_hash), and the Ethereum receiveMessage hash that may not exist yet (destination_transaction_hash, matching the single required param). It lacks format expectations but conveys availability semantics the schema does not.

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 (observe, verify, reconcile) over a specific resource (CCTP bridge across Base and Ethereum) and names the artifacts involved. It is clearly distinguishable from siblings like inspect_bridge or observe_swap, though it never explicitly contrasts itself with them.

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 line about source-only observation being reported as an evidence gap rather than completion implies this is a post-bridge-verification step, but no explicit when-to-use, prerequisites, or alternatives (e.g., preflight_bridge, inspect_bridge) are named. Usage is inferable rather than stated.

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