invariance_signal_emit

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

Annotations already indicate a non-read-only, non-destructive operation. The description adds valuable behavioral details: severity defaults to 'info' and run_id/node_id auto-fill from environment variables when present. No contradiction with annotations exists.

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—first states the core purpose, second covers the default/fallback behavior. Every word earns its place, and critical information is front-loaded.

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 tool with 7 parameters and no output schema, the description covers purpose, defaults, and environment variable fallbacks, which is sufficient for correct invocation. It does not discuss return values, but that is not required without an output schema.

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%, so all parameters are already documented. The description enriches this by clarifying the severity default and the run_id/node_id fallback logic, going beyond the schema's static parameter descriptions.

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 a specific verb ('Emit') and resource ('manual signal (alert/notification)'), and adds context on typical attachment to a run/node and purpose ('flag noteworthy events'). It distinguishes itself from sibling signal tools (list/get/acknowledge/resolve) by emphasizing the manual emission action.

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 describes typical use cases (attached to runs/nodes, flagging events for review/downstream automation) but does not explicitly name alternatives or when not to use it. An agent can infer its role among signal siblings, but the guidance is not exhaustive.

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