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

Annotations already mark readOnlyHint=true, and the description reinforces this with 'READ-ONLY' and 'never records usage — it does not expose send_event or lock', adding concrete behavioral context beyond the annotation. It also identifies the underlying Autumn API endpoint, giving the agent useful operational detail.

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 compact and front-loaded: it opens with the read-only nature and core question, then adds the endpoint and the key usage-related exclusion. Every phrase earns its place and there is no filler or redundant elaboration.

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?

For a moderately simple check tool, the description covers purpose, read-only behavior, the usage-recording exclusion, and the API endpoint. Parameter details are covered by the schema, which also hints at the returned 'allowed' flag. Nothing essential is missing for an agent to select and invoke this tool 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?

The description does not discuss parameters, but all five parameters are already fully documented in the input schema (100% coverage). Since the schema carries the semantic weight, the description adds little beyond overall tool purpose, so baseline 3 is appropriate.

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 states the specific action ('check') and resource ('customer access to or balance of a feature'), making it easy to distinguish from sibling tools. It explicitly positions itself as a read-only entitlement check and contrasts with usage-recording tools by saying it does not expose send_event or lock.

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 is for checking access/balance, not for recording usage. It explicitly says the tool never records usage and lacks send_event/lock, which helps an agent avoid using it for metering. However, it does not name specific sibling alternatives or spell out 'use tool X when...', so routing is slightly less explicit.

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