ClockNext: update credit

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

Beyond the annotations, the description discloses destructive semantics: omitted fields are cleared, pricing is re-grounded, and changing agentKey re-points runtime signals. This is exactly the kind of behavioral context annotations do not provide, and it does not contradict readOnlyHint/idempotentHint.

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 sentences front-load the most important fact (full rewrite, not patch), then add prerequisites and cautions without redundancy. Every sentence carries operational value.

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 7-parameter mutation with no output schema, the description covers destructive behavior, prerequisite reads, pricing behavior, and the agentKey risk. It loses a point because the isActive advice conflicts with the closed input schema and the return/result shape is not mentioned, but overall it is unusually thorough.

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 covers all parameters, so baseline is 3. The description adds meaning by explaining the models mixer re-grounds pricing and that agentKey is the durable identity whose change deliberately re-points signals. However, it references 'isActive' which is not present in the schema, slightly muddying parameter guidance.

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 opens with 'Replace a credit by id with its COMPLETE new definition', giving a specific verb and resource and distinguishing it from a partial patch. It also notes pricing is re-grounded 'same as create', which orients it among create/update/archive siblings.

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?

It gives an explicit prerequisite: read the current credit with clocknext_get_credit first. It also gives a concrete use case for toggling active state. It does not name alternative tools to avoid, but the full-rewrite framing makes the update-vs-create distinction clear.

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