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

With no annotations, the description carries the full burden and does meaningful work: it discloses both side effects (an income transaction is created on the account, the portfolio cash balance decreases). It stops short of stating reversibility, idempotency, or permission requirements for what is clearly a money-moving mutation.

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 sentences, each earning its place: the operation, the resulting state change, and the alternative-route condition. The core action is front-loaded and nothing is redundant.

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 six-parameter mutation with no output schema and no annotations, the description supplies the essential causal model (transaction created, balance decreased) and the key routing rule. What's missing is whether the operation can be undone (unlink_transaction_from_portfolio exists as a sibling) and what the call returns.

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 all six parameters are already documented, including the positive-decimal constraint and the source/destination ID provenance. The description adds only directional framing (portfolio is source, account is destination), which the schema's own descriptions largely cover; baseline 3 is appropriate.

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 and direction ('Withdraw cash from an investment portfolio into a regular account'), and the directionality distinguishes it from the reverse sibling transfer_account_to_portfolio without the agent needing to open either 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?

It explicitly routes to link_transaction_to_portfolio with the selecting condition 'when the bank transaction already exists', which is exactly the discriminating case. It doesn't mention the mirror-image sibling transfer_account_to_portfolio or warn against double-counting an already-linked transfer, so it stops just short of full when/when-not coverage.

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