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

With no annotations, the description carries the full behavioral burden. It does disclose useful behavior beyond the structured fields: the result may be absent ('if available') and the payload is wrapped in a 'values' object. However, it omits any mention of auth/permission requirements or behavior when no wallet is linked (error vs. empty), so disclosure is partial.

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?

Front-loads the purpose in one sentence, then the param and return notes. It is compact with no filler. The '@return ... in the "values" object' phrasing is slightly awkward but still earns its place by naming the response envelope.

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 single-parameter read tool with no output schema and no annotations, the description covers purpose, parameter, and a rough return shape, which is adequate to invoke it. It is not complete: it says nothing about when the linkage is missing or what permissions are needed, leaving gaps an agent may need.

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 0%, so the description must compensate, and it does supply the one meaningful fact the schema lacks: customer_id is 'the customer's database id'. That is the minimum needed but adds no format, range, or lookup guidance, so it only partially compensates for the coverage gap.

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 ('Returns') and a specific resource ('the customer's linked Netfluid wallet_fk and account_fk'), which is enough to distinguish it from the sibling mutator paywall__customer_link_wallet_account. The terms 'wallet_fk'/'account_fk' are jargon but the intent (fetch an existing linkage) is clear. It stops short of an explicit differentiation statement against siblings.

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 description offers no guidance on when to call this versus alternatives such as paywall__customer_link_wallet_account or paywall__wallet_accounts_and_balance. There is no statement of prerequisites, context, or exclusions. The reader must infer usage entirely from the name.

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