UpdateMessageClassMessage

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

No annotations are provided, so the description carries the full behavioral burden. It does disclose a genuinely useful trait — that the operation upserts rather than failing when the message is absent — which is meaningful idempotency context. However, it omits transport/lock behavior, whether unmentioned fields (like description) are reset, and any authorization prerequisites.

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?

Two tightly written sentences with no filler; the primary action is front-loaded and the important upsert caveat follows immediately. Every clause earns its place.

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 mutation tool with no annotations, no output schema, and six parameters, the description covers the basic action and the upsert edge case but says nothing about transport handling, locking, or side effects on unspecified fields. Adequate as a minimum-viable definition, but incomplete for safe invocation.

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 all six parameters, including the placeholder syntax for msgtext and the transport_request caveat. The description only loosely gestures at 'text / flags', adding little beyond what the schema fields already say, so the baseline 3 applies.

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 (Change) plus resource (text/flags of a message in an ABAP message class) and names the underlying table (T100), so the agent knows exactly what is being modified. It does not explicitly differentiate itself from the sibling CreateMessageClassMessage — in fact the upsert clause partly overlaps with it — but the core purpose is unambiguous.

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 'existing' implies the intended case, but there is no explicit guidance on when to use this versus CreateMessageClassMessage or GetMessageClassMessage. The upsert caveat actually muddies the boundary with the create sibling rather than clarifying when each should be chosen.

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