update_system_tunable

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

Annotations already indicate this is a mutating (readOnlyHint: false), idempotent (idempotentHint: true), non-destructive (destructiveHint: false) operation. The description adds no behavioral context beyond 'update', such as whether changes require a reboot, how apply_immediately affects application, or what happens if the tunable does not exist. It is consistent with annotations but does not enrich 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?

The description is a single, concise sentence: 'Update an existing system tunable by ID'. It is front-loaded and contains no filler or redundant wording. Every word contributes to understanding the tool's core function.

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 the tool has 5 parameters, full schema descriptions, and annotations, the description is minimally adequate but leaves gaps. It does not mention how to obtain the tunable_id (beyond schema), when changes take effect, or any special considerations like apply_immediately handling. It is sufficient for a well-schema'd tool but lacks the richer context typically needed for mutating operations.

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?

The schema has 100% coverage with descriptions for all parameters, so the baseline is 3. The description itself adds no parameter-level meaning; it only mentions 'by ID' which is already captured in the tunable_id parameter description. The schema's description for tunable_id usefully references search_system_tunables, but the tool description contributes nothing extra.

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 'Update an existing system tunable by ID' uses a specific verb (update) with a clear resource (system tunable) and identifies the key parameter (ID). It effectively distinguishes this tool from create/delete/search siblings by indicating it modifies an existing entity.

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 provides no explicit guidance on when to use this tool versus alternatives like create_system_tunable or delete_system_tunable. While the verb 'update' implies existing entities, there is no mention of prerequisites, exclusions, or when to prefer this over other update tools. It leaves usage entirely to inference.

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