start_turn

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

Annotations already declare readOnlyHint=false, idempotentHint=false, and destructiveHint=false, so the lower bar applies. The description adds side-effect specificity by saying exactly what mutation occurs: a thread is created and an initial turn is submitted. This goes beyond the annotations without contradicting them.

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 filler. Each phrase adds either the core action or the required selecting scope, making it easy for an agent 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?

The description covers the essential action and an output schema exists, but it omits useful workflow context: that environment/project IDs may come from list_projects/list_environments, that continue_turn handles subsequent turns, and that modelSelection is optional. These omissions leave some decision-making to the agent.

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%, so the description must compensate. It maps well to environmentId and projectId, and 'first turn' indirectly implies the prompt parameter. However, it does not explain the optional modelSelection object, its instanceId/model fields, or how options behave, leaving a meaningful gap.

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 states a specific verb ('Create') and resource ('a thread') plus the additional action of submitting its first turn. The 'first turn' phrasing distinguishes it from the sibling continue_turn, and 'explicitly selected environment and project' clarifies scope without needing to inspect the schema.

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?

There is no explicit when-to-use statement or named alternative. However, 'Create a thread' and 'first turn' strongly imply this is the entry-point tool, with continue_turn as the implicit follow-up; that guidance is inferable but not stated.

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