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

Annotations already declare this is a write operation (readOnlyHint=false) that is non-destructive and closed-world, so the safety profile is covered. The description adds the deployment-must-be-running precondition and the effective replica range, but says nothing about the effect of scaling down (replica termination, rollout behavior) or whether the operation is immediate.

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 the verb, resource, and constraint; no filler, no redundancy.

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 simple two-parameter, fully-documented, no-output-schema tool with clear annotations, the description covers what an agent needs to invoke it. The remaining gap is behavioral outcome (what scaling does to running replicas), which is minor at this complexity level.

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%, with both deploymentId (UUID) and replicas (1-10 with min/max) documented in the schema itself, so the baseline is 3. The description merely restates the bound already encoded in the schema and adds no format or identifier guidance.

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 (scale) plus resource (running deployment) and the target value, which clearly separates it from siblings like nexusai_deploy_start, _stop, and _redeploy. It does not, however, explicitly name or contrast itself with any alternative, so it falls short of a 5.

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 word 'running' implies the prerequisite that the deployment must already be started (vs. nexusai_deploy_create/start), which is useful but only implied. There is no explicit when-to-use/when-not-to-use statement or reference to sibling tools.

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