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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so 'Read-only' is redundant. What the description adds beyond the annotations is the ordering constraint (fetch the contract first) and the specific content of the response, which is what an agent needs to know before drafting a function. No token-size or caching caveats, so not a 5.

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 sentences, both front-loaded: the return payload first, the call timing second. Every clause names a distinct piece of returned content; nothing is padding.

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?

With no parameters, no output schema, and full annotation coverage, the only gaps an agent could have are 'what comes back' and 'when do I call it' — both are answered explicitly. The tool is a documentation fetch, and the description fully discharges that scope.

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?

Zero parameters, so there is nothing to disambiguate; the baseline applies. The description correctly spends no words on parameter semantics and instead covers return content.

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 and resource ('Return the exact Code function contract') and then enumerates the payload: main(input, context), runtime context fields, sandbox limits, test-case shape, examples. That enumeration distinguishes it from the similarly named sibling agent_functions_get_code, which plausibly returns actual code rather than the spec.

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?

'Call before drafting or editing a Code function' gives an explicit trigger condition tied to the sibling workflows (create_code, update_code, create_http). It stops short of naming alternatives or stating when not to call it, so it is clear context rather than full routing guidance.

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