fiken_send_invoice

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

The description indicates a mutation (sending) which aligns with readOnlyHint=false. However, it omits important behavioral details: whether the invoice status changes, if attachments are included automatically, what happens on failure, or if multiple methods are attempted in sequence. The description adds minimal value beyond the annotation.

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 sentence, which is concise but under-specified. It sacrifices content for brevity. For a tool with 10 parameters, this is insufficient. It is front-loaded with the verb, but the lack of detail makes it less useful.

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?

Given the tool complexity (10 parameters, 3 required), no output schema, and no annotation beyond readOnlyHint, the description is grossly incomplete. It should explain sending behavior, required setup, and what the tool produces or modifies. Currently, it fails to provide adequate context for correct invocation.

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?

With schema description coverage at only 10% (only 'method' has a brief description), the description should compensate by explaining parameter meanings. It does not mention any parameter details, leaving the agent to guess the purpose of fields like message, mobileNumber, recipientName, etc.

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 the verb 'sends' and the resource 'invoice' with specific methods 'email and/or EHF'. This clearly indicates the tool's primary action, distinguishing it from tools that retrieve, create, or update invoices. However, it could be more precise by noting that it sends an existing invoice to a customer.

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 provides no guidance on when to use this tool versus alternatives like fiken_send_credit_note or fiken_send_offer. It does not mention prerequisites (e.g., invoice must be finalized) or exclusions. No contextual hints are given.

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