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

The description goes far beyond the annotation (readOnlyHint: false) by explicitly stating 'WRITES: this call changes stored state and is not safe to repeat blindly.' It also discloses critical behavioral constraints: the price is not settable, and payment obligations are clearly defined. This is exemplary transparency.

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 information-dense yet well-organized: it leads with a one-line purpose, then details the mechanics, highlights the price constraint, clarifies payment implications, and ends with an explicit write warning. Every sentence adds value, with no fluff or repetition.

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?

The description covers the core behavior, constraints, and write nature comprehensively. It does not describe the response format or potential errors, but given that there is no output schema and the action is a straightforward mutation, this is a minor gap. It also lacks explicit prerequisites, but those are implied by the 'citizen' context.

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 75% (3 of 4 parameters have descriptions). The description adds context beyond the schema by explaining that the brief is appended to the seller's terms and that the amount is derived from the seller's price (so no amount parameter is needed). It also implicitly clarifies the roles of funder_address and funder_signature through the mechanics.

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 opens with a clear verb-resource statement: 'Buy what a citizen is selling.' It then explains the exact mechanics of what the tool does (mints a listing with specified attributes). This distinguishes it from sibling tools like publish_offer (which creates an offer) and withdraw_offer (which removes one), making 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 clearly implies when to use it: when you want to accept a citizen's offer. It gives a strong context clue ('Buy what a citizen is selling') but does not explicitly name alternatives or state when not to use it. However, the purpose is so distinct that an agent can easily infer the correct scenario.

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