The budget and usage report for a scope (PAID $0.25)

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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered. The description adds genuinely useful behavior beyond that: the tool is paid ($0.25 USDC via x402 on eip155:8453/Base) and is a remote GET route, which tells the agent a payment flow is involved before invoking it.

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?

Two short sentences, purpose stated first, then payment/route metadata — no filler. Minor redundancy in restating the price already present in the title.

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?

An output schema and rich annotations cover return values and safety, so the description needn't explain those. Still, for a paid endpoint in a crowded treasury/quota family, it omits what the report actually contains and how it relates to v1_agent_treasury_budget or v1_budget_preflight, which is the gap that matters for correct selection.

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 three query parameters are already documented structurally; baseline 3 applies. The description adds nothing about what `scope_id` or `scope_kind` mean or how `requestId` is used for idempotency.

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 resource — a budget and usage report scoped by `scope_id` — so an agent knows what data comes back. However, it is a noun phrase with no verb and gives no differentiation from closely named siblings such as v1_agent_treasury_budget or v1_budget_preflight, which an agent could easily confuse with it.

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 no when-to-use guidance, no prerequisites, and no mention of alternatives despite a dense cluster of treasury siblings (budget, authorize, commit, release, spend_anomaly). The only context offered is the route and price, which doesn't help select the tool.

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