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

With no annotations, the description carries the full burden and does well: it discloses that the operation is non-destructive (records are marked unlinked, not deleted), that history visibility changes, and that a finance:write scope is required. It does not cover reversibility (can the link be restored?) or partial-failure behavior.

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?

Three short sentences, each front-loaded and earning its place: the action, the non-deletion guarantee, the state effect, and the auth requirement. No filler or restatement of the tool name.

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 two-parameter mutation tool with no annotations and no output schema, the description covers the key facts an agent needs (effect, non-destructiveness, required scope). It omits what happens if IDs are not currently linked and whether the change is reversible, which are the remaining gaps.

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% with only two parameters, so the schema already documents subscriptionId and transactionIds. The description adds no syntax, format, or constraint detail (e.g., whether IDs must currently be linked), leaving it at the baseline.

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 (unlink), resource (transactions), and scope (from a subscription), and immediately distinguishes the operation from deletion ('without deleting them'), which separates it from siblings like delete_transaction. An agent can identify the operation without opening the schema.

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 phrase 'without deleting them' implicitly signals when to prefer this over a delete operation, and 'excluded from subscription history' hints at the effect desired. However, no alternative tool is named (e.g., its inverse link_transactions_to_subscription, or delete_transaction) and no explicit when/when-not condition is given.

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