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

Adds real information beyond the annotations: the same target_key overwrites your own entry, the id is preserved, no history is kept, and the secret is encrypted at rest and never returned. That last point is the key behavioral fact for a credential tool. Minor tension: an overwrite with "keine Historie" loses the prior credential, while destructiveHint=false, and the description never reconciles this.

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 dense sentences that front-load the create-or-replace behavior, then the secret handling, followed by a short keyword line for retrieval. Nothing is padded and the most decision-relevant fact comes first.

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 5-parameter mutation with no output schema, the definition covers the write semantics, idempotency, and what is never returned, which is what an agent needs to call it safely. It omits error/validation behavior and permission requirements, the only notable gap.

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 coverage is 100%, so baseline is 3, but the description adds the crucial semantic that target_key is the upsert identity key (same key = replacement), which the schema only calls "Technischer Name". It also explains the fate of the secret field (encrypted, never returned), which the schema does not state.

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?

"Verbindung anlegen oder ersetzen" gives a specific verb pair and resource, and the EN keyword line reinforces the searchable identity (connection, credential, upsert). It does not name the adjacent connection tools (onto_connection_check, onto_connection_remove, onto_connection_index) to differentiate itself, so it stops 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?

Use is implied by the upsert semantics (call it to store or refresh a credential), but there is no explicit when-to-use vs. when-not, and no pointer to onto_connection_check for validating a connection before or after saving. The agent must infer the workflow from sibling names alone.

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