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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, and the description goes well beyond them: response size (32 KB), rate limit (60 RPM), pricing mechanics ('?demo=true' or L402 at 20 sats), and the failure mode (HTTP 400 if invalid). For a payable edge call these are exactly the facts an agent needs before invoking.

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-loaded with purpose before routing guidance, then operational facts, with no filler sentences. It is dense—several parentheticals are packed into a single clause near the end—which costs some scannability, but every clause carries distinct information.

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?

An output schema exists, so return values need not be explained; the description instead covers the things the schema cannot: payment/auth mode, rate limit, payload size, error behavior and the budget default. Nothing an agent needs to call this correctly is missing.

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% and both parameters, including the enum values, are already documented. The description only restates the 'objective' input and the 'lowest_sats_deterministic' default that the schema's own description carries, so it adds little semantic value here. Baseline 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 pair: maps a natural-language goal to an ordered sequence of MCP tool calls, naming the exact artifacts produced (endpoint paths, JSON-RPC 2.0 payloads, cumulative satoshi cost). It also distinguishes itself from the nearest sibling, compile_xml_agent_prompt, in the same sentence, so an agent can route without opening either schema.

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?

Gives an explicit trigger ('Use when an autonomous agent needs to plan which MCP tools to chain together to solve a multi-step objective within a satoshi budget') and an explicit exclusion with a named alternative ('for compiling a static XML system prompt ... use compile_xml_agent_prompt instead'). The when/when-not/alternative triple is complete.

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