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

Annotations already provide readOnlyHint=true, idempotentHint=true, destructiveHint=false, covering the safety profile. Description adds context that interrupted streams still have status/billing, which goes beyond annotations. It doesn't disclose not-found behavior or response shape, but with annotations present, a 3 is appropriate.

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?

One sentence, front-loaded with 'Status and final billing', all content is useful and no fluff. The edge case about interrupted streams earns its place.

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 simple read-only lookup with one parameter, the description covers purpose, input semantics, and mentions interrupted streams. No output schema exists, but it states what's returned (status and billing). It could provide more context on the domain meaning of 'request', but overall adequate.

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 must compensate. It connects request_id to 'previous Layrcake request', adding meaning beyond the schema's format/pattern. It doesn't explain how to obtain the ID or what 'request' means exactly, so 3 is fair.

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?

Description states a specific verb ('Status and final billing') and resource ('previous Layrcake request by request_id'), and distinguishes from siblings like get_operation and get_usage by focusing on final billing and interrupted streams. It clearly answers what the tool does.

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?

Usage is implied: use when you have a request_id and want status/billing. No explicit alternatives or exclusions; it doesn't mention when to prefer get_operation or get_usage. The 'including requests whose stream was interrupted' hints at a use case but doesn't name sibling tools.

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