create_predefined_metric

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

With no annotations, the description carries the full burden but only says it 'creates'. It doesn't disclose what happens on a duplicate or unknown name, whether the metric becomes active in state, or whether it mutates the session like other tools in this family.

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?

A single front-loaded sentence with no waste, but the brevity reflects under-specification rather than efficient communication.

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?

An output schema exists so return values needn't be described, but for a state-mutating creation tool with zero annotations and an undocumented required parameter, the description leaves critical calling information missing.

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 coverage is 0% for the single parameter, so the description must compensate and doesn't. It never clarifies whether metric_name is a free-form label or must match a known predefined metric identifier.

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 verb 'Creates' and resource 'predefined spacetime metric' are stated, but 'predefined' just echoes the tool name without explaining what a predefined metric actually is. It is distinguishable from create_custom_metric only by inference from the name, not from the description.

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?

No indication of when to use this versus create_custom_metric or search_predefined_metrics, no prerequisites, and no note on whether the metric must first be discovered via search. The agent must guess the workflow.

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