sendInvoice

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 does add one useful fact — the sent Message is returned on success — which matters because no output schema exists. However, it omits critical behavioral context for a payment operation: sending an invoice kicks off a payment flow, generates a pre-checkout/checkout query to the bot, and presents the user with a Pay button. This is a significant gap for a tool with zero annotation coverage.

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?

Two sentences with zero waste. The core action is front-loaded, and the second sentence about the return value earns its place given that no output schema is available to communicate the result type.

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 29-parameter payment operation with no output schema and no annotations, a two-sentence description is insufficient. The schema covers parameter semantics, but the tool's role in the payment lifecycle, its relationship to createInvoiceLink, and its side effects on both user and bot are entirely undocumented.

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 the input schema already documents every one of the 29 parameters in detail. The description adds no parameter-level information beyond the schema, so the baseline of 3 applies.

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 and resource — 'Send an invoice to a user' — which clearly separates it from the many sibling send-* tools (sendMessage, sendPhoto, sendPoll, etc.). It does not explicitly name its closest sibling createInvoiceLink, so the distinction between direct-send and link-based invoicing is left to inference. The scope is otherwise unambiguous.

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?

No when-to-use guidance is provided. The description never mentions that this is the direct-send alternative to createInvoiceLink, nor the conditions that would select one over the other. No prerequisites (e.g., requiring a payment provider token) or exclusions are stated.

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