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

The description adds valuable behavioral context beyond the annotations: it explicitly states 'Never submits a transaction', notes the requirement for the caller's session capability token, and says the tool 'advance[s] the workflow', indicating a state-changing effect consistent with readOnlyHint=false. This is useful and not a contradiction.

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 short, purposeful sentences. The main action is front-loaded, followed by the auth requirement and the key safety guarantee. No filler or repetition of schema details.

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 description covers purpose, auth, and transaction-safety, but with no output schema and 0% parameter documentation, it leaves meaningful gaps: what 'bridge/destination output' concretely refers to, how idempotency_key works, and when transaction_hash should be supplied. It is adequate for selecting the tool but not fully self-sufficient for invoking it correctly.

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 0%, so the description bears the burden of explaining parameters. It only clarifies that a session capability token is required, which maps to session_token. It does not explain the meaning or purpose of session_id, idempotency_key, or the optional transaction_hash, leaving important semantics to inference from parameter names.

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 clearly identifies the action (observe), the resource (caller's already-produced bridge/destination output for a v2 session), and the workflow side effect (advance the workflow). It is more specific than a tautology and the 'Never submits a transaction' line helps separate it from action/submission tools, though it does not explicitly name a sibling alternative such as assetfare_v2_session_observe_source.

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 description provides clear context: this tool is for observing already-produced output in a v2 session, requires a session capability token, and advances the workflow without submitting a transaction. This implies when it should be used, but it does not explicitly state when-not to use it or name alternatives.

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