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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so safety is covered. The description adds genuine domain behavior beyond that: the precedence rule over institution_url and the meaning of url_host as suitable display text. It stops short of describing pagination or ordering, but adds real context against a lowered bar.

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 core purpose, then adds precedence semantics and a returns block. Every sentence carries information, though the Returns block is a touch verbose for a zero-parameter list tool. No filler or tautology.

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?

Low-complexity, read-only, zero-parameter tool with no output schema, and the description compensates by documenting the return object shape (payment_links array with id, label, url, url_host, updated_at). Nothing essential for correct invocation is missing, though pagination/ordering behavior is left unspecified.

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?

The tool takes zero parameters, so the schema baseline of 4 applies. There are no parameters to misinterpret, and the description usefully documents the shape and fields of the returned objects instead.

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 ('List') and resource ('payment links'), and goes further by defining what a payment link actually is (an external URL the user provided for a specific payment context). The intent is unambiguous against siblings like save_payment_link and delete_payment_link, though those siblings are not named explicitly.

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?

Usage is implied rather than stated. The note that a saved payment link takes precedence over institution_url for a matching context explains the data's semantics but does not tell the agent when to call this tool versus list_accounts or get_account_details. No explicit when/when-not guidance.

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