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

With no annotations, the description carries full burden and excels: it discloses the two-step payment flow (call without x_payment to get terms, sign, then call again), validation before payment, the ordered mapping of results to requests, and cursor semantics (store next_cursor per feed). It leaves no behavioral ambiguity.

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 dense but every sentence earns its place: it front-loads the core value ('Up to 10 ... behind ONE payment'), then efficiently covers mapping, cursor behavior, validation, and payment. No fluff or repetition, and the structure flows logically.

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's complexity (batching, payment, cursors) and lack of output schema, the description covers all essential aspects: request mapping, response cursors, payment negotiation, validation, and a pointer to the pricing tool. An agent can call it correctly without further inference.

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 coverage is 100%, but the description adds substantial meaning beyond schema: it explains that data.results[i] corresponds to requests[i], clarifies the cursor usage for 'since', and details the x_payment parameter's role in the paid flow. This goes far beyond the schema's baseline descriptions.

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 clearly states the tool batches up to 10 news reads (headlines/ai/crypto/search) behind one payment, distinguishing it from single-read siblings like 'news' and 'news_poll'. The verb 'batch' and explicit resource scope make its purpose 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?

The description implies use for multiple reads ('several news reads in one paid call') and mentions the free 'pricing' tool as an alternative for price lists, but it does not explicitly name alternatives like 'news' for single reads or state when not to use the batch tool. It provides clear context but lacks explicit exclusions.

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