gemini_models

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered; the description still adds cost and latency characteristics ("free and quick") plus the crucial chaining instruction that the returned id feeds the `model` parameter of gemini_ask, gemini_research and gemini_code. It stops short of stating pagination, quota, or what happens on an empty model list.

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?

Front-loaded with purpose, then usage rule, then return shape; two tight sentences plus a Returns block, with zero filler. The Returns block slightly duplicates information an output schema may already carry, but it earns its place by showing the id-to-`model` handoff.

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 zero-argument, read-only discovery tool with an output schema, this covers purpose, cost/latency, trigger conditions, default fallback, and how the result plugs into sibling tools. Nothing an agent needs to call it correctly and act on the result is 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?

There are zero input parameters, so the baseline is 4 and nothing about inputs needs explaining. The description instead documents output semantics (one "id — name" line per model) and how that id is consumed downstream, which is useful but is output guidance rather than input semantics.

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 ("List the models the user's Google account can use through the Antigravity CLI") with concrete scope, so an agent can distinguish it from gemini_ask, gemini_research, gemini_code and the jules_* siblings without opening a 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?

Gives an explicit trigger ("Call it when the user asks for a specific or stronger model") and an explicit default path ("otherwise the gemini_* tools use agy's default"), which is exactly the when/when-not routing an agent needs.

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