update_instance

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It indicates that the tool updates metadata and currently only supports description, but it does not disclose side effects, idempotency, permission requirements, what happens when the description is omitted, or what the tool returns. The 'or get' wording also promises a retrieval behavior that is not explained.

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, front-loaded sentence with the primary verb 'Update' at the start and no filler. The 'or get' clause is unnecessary and creates ambiguity, so the sentence is concise but not fully clean in what it communicates.

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?

This is a mutation-oriented tool with no annotations and no output schema, so the description needs to compensate with more behavioral and usage context. The schema covers parameters well, but the description leaves unresolved questions about read-vs-write behavior, return values, and how this relates to list_instances and archive_instance, making it incomplete for reliable tool selection.

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%, so the schema already documents instance_id and description, including the 'omit to leave unchanged' behavior. The description adds only marginal confirmation that description is the sole metadata field, without enriching the parameter semantics beyond the schema.

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 names a specific verb ('Update') and resource ('an instance's metadata') and narrows scope to 'currently only description,' which helps distinguish it from broader metadata tools. However, 'Update or get' introduces ambiguity about whether this tool also retrieves metadata, and it does not explicitly contrast itself with the sibling list_instances tool.

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 guidance about when to use update_instance versus create_instance, list_instances, or archive_instance. The phrase 'currently only description' implies a narrow use case, but no alternatives or exclusions are stated, leaving the selection logic to inference.

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