update_stream

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

With no annotations provided, the description carries the behavioral disclosure burden. 'Only the given fields change' is a useful and explicit partial-update guarantee: unspecified fields keep their value. However, it does not disclose permissions, side effects, irreversibility, or what response to expect from this mutating operation.

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 extremely concise and front-loaded: the verb, resource, and the only meaningful behavioral constraint are stated in two short sentences. There is no filler or redundancy, and the schema carries the remaining parameter detail.

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 4-parameter update tool with a fully documented schema, the core partial-update semantics are present. However, there is no output schema and no description of the return value or error behavior, and the relationship to archive_stream is left unresolved, so an agent has some gaps when invoking it.

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 individual parameter meanings are already fully documented. The description adds one valuable cross-parameter semantic—omitted optional fields are left unchanged—but does not need to explain each parameter further.

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 identifies the action ('Update') and the resource ('a message stream'), and adds the key partial-update semantic that only provided fields change. This is enough to distinguish it from create/get/archive siblings at a basic level, though it does not explicitly name the dedicated archive_stream alternative.

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?

No guidance is given for when to use this tool versus siblings such as archive_stream, which overlaps on the archived field. The description implies general stream updating but does not state exclusions, prerequisites, or routing conditions, so the agent must infer usage.

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