Update invoice

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

With no annotations, the description carries the full burden of behavioral disclosure. It adds one genuine behavioral fact — updates are rejected once issued/locked — which is valuable. However, it does not disclose whether the `fields` payload merges with or fully replaces existing values, nor any permission requirements or side effects of the 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?

The description is a single six-word sentence with the action front-loaded and the critical constraint packaged in a parenthetical. Every word earns its place with zero filler, though it is quite terse.

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 mutation tool with no annotations, no output schema, and two undocumented parameters (one a nested object), the description supplies only the lock constraint. It omits fields-object semantics, merge/overwrite behavior, and return-value expectations, so an agent lacks enough detail to safely invoke it correctly.

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 for the undocumented parameters. It clarifies that `fields` holds updatable invoice fields, but it does not specify what keys are valid inside the object nor the expected format of `invoiceId`, leaving an agent to guess the payload shape for a nested-object parameter.

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 states a specific verb ('Update') and resource ('invoice fields'), and adds a differentiating constraint: '(blocked once issued/locked)'. This clearly separates it from siblings like gambot_create_invoice and gambot_issue_invoice, though it does not name them 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?

The parenthetical '(blocked once issued/locked)' implies the tool is only usable on unissued/unlocked invoices, giving a useful when-not-to-use signal. However, it never explicitly mentions alternatives such as gambot_create_invoice or gambot_issue_invoice, leaving routing between siblings to inference.

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