counter_increment

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

No annotations are provided, so the description carries the full burden. It discloses a key side effect: 'Creates the counter if it doesn't exist.' This is essential behavior beyond the basic increment. It also mentions decrement capability via schema description, but the main description focuses on increment and auto-creation, which 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?

The description is two sentences, front-loaded with the primary action, and includes a purpose statement. No redundant wording or unnecessary details. Every sentence contributes 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?

This is a simple tool with no output schema. The description covers what it does, auto-creation behavior, and typical use cases. It does not describe the return value (e.g., new counter value), but that is not critical for invoking the tool correctly. Sibling tools are distinct and self-explanatory.

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%: both counter_id and amount are described in the input schema. The description adds context about auto-creation for counter_id, but does not add new syntax or format details beyond the schema. Thus, 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 action ('Increment a counter'), the resource (counter), and the configurable amount ('by a specified amount, default: 1'). It distinguishes from siblings like counter_get, counter_reset, and counter_delete by specifying the increment operation.

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 gives explicit usage context: 'Use this to track iterations, processed items, or any counting task.' However, it does not explicitly mention alternatives or when not to use this tool, though the sibling names (counter_get, counter_reset, etc.) make the distinction obvious.

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