cloud_insts_add_placegrp

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

With no annotations, the description carries full behavioral disclosure burden. It explains that the instance must not already be in a server group and that bare metal is unsupported. It also details parameter resolution for project and region. However, it omits side effects, return value, permissions, and error cases, leaving gaps.

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 structured with a main sentence, constraints, args list, and note. It is somewhat lengthy but each part adds information. The args list partially duplicates the schema but adds context. Could be trimmed, but overall acceptable.

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 8 parameters (4 required), no output schema, and no annotations, the description should cover more. It lacks any description of return values, error conditions, or success behavior. It does address project/region resolution, but missing instance_id explanation and full behavioral details make it incomplete for an agent to fully understand the tool's usage and effects.

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 explains servergroup_id as an affinity type and provides resolution notes for project_id and region_id. However, it fails to describe the required instance_id parameter at all, and extra_* parameters only get superficial descriptions ('Send extra headers'). This leaves significant meaning absent.

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 'Add an instance to a server group,' specifying the verb and resource. It distinguishes from sibling 'cloud_insts_rm_placegrp' by the opposite operation. Additional constraints like instance must not already be in a group and bare metal exclusion further clarify purpose.

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 includes when to use (add to server group) and conditions (instance not already in group, not bare metal). It provides guidance on resolving project_id and region_id via sibling tools. However, it does not explicitly list alternatives or when not to use beyond the stated constraints.

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