metrics_metric_gauge

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

With no annotations, the description must disclose behavior. It correctly indicates that gauges hold the last value set and that the tool returns updated state. However, it does not mention side effects, persistence, overwriting behavior, or error conditions, leaving some behavioral aspects unclear.

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 extremely concise, consisting of two sentences that deliver the essential information. The first sentence states the purpose, and the second adds context and return value. No extraneous words, making it easy to parse quickly.

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?

Given no annotations and 0% schema description coverage, the description covers the core purpose, example uses, and return value. However, it omits details about parameter behavior (especially tags), potential errors, and whether the gauge is created if missing. While adequate for a simple tool, it leaves gaps for an agent to infer.

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 schema coverage is 0%, so the description should compensate. It implicitly explains 'name' and 'value' through the context, but the 'tags' parameter is not described at all. The description adds limited meaning beyond the schema, especially for the optional parameter, resulting in partial clarity.

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 tool's function: 'Set a gauge metric to a specific value.' The verb 'Set' and the resource 'gauge metric' are specific, and the examples (queue depth, memory usage) further clarify. It distinguishes itself from sibling metrics tools like increment, reset, and get by specifying that this sets an absolute value.

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 usage context by explaining that gauges are useful for queue depth, memory usage, and active connections. This implies when to use this tool over alternatives like increment. However, it does not explicitly state when not to use it or name alternative tools, which would improve guidance.

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