start_run

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

Annotations already declare readOnlyHint=false and destructiveHint=true, so the agent knows this mutates state. The description usefully adds that execution happens in the background and that confirm=true is required, but it never explains what the destructive action actually does, whether it can be cancelled, or how the run is tracked (get_job_status exists as a sibling).

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 short sentences, both earning their place, with the core action front-loaded before the prerequisite. The brevity is appropriate in structure though it contributes to the under-specification noted elsewhere.

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 destructive, mutating tool with four undocumented parameters, no output schema, and no annotation-derived detail on effects. For a background job starter, the description should explain the date range semantics, environment scoping, and how to follow the run, none of which is present.

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 0% across four parameters, so the description carries the full burden. It only clarifies confirm=true and leaves start, end, and environment completely undefined in both schema and description, including what format the date strings expect or what environment means.

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?

States a specific verb and resource ('Start a scheduled model run') and adds the key behavioral qualifier 'in the background.' It is clear what the tool does, but it never distinguishes itself from close siblings like run, start_plan, or apply_plan, leaving the agent to infer which entry point applies.

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?

'Requires confirm=true' is a prerequisite, not usage guidance. There is no statement of when to choose start_run over run/start_plan/apply_plan, nor any when-not condition, despite several overlapping siblings.

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