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

Annotations only carry readOnlyHint=false, so the description has to do the heavy lifting and it does: it discloses that publication creates no entitlement or liability, that price/terms are hashed and immutable after ordering, that the buyer funds the minted listing, that bind_key is required or nothing can be paid, and that the write is not safe to repeat. This is exactly the behavioral context annotations omit.

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 the orientation cue 'SELL SIDE' and a trailing 'WRITES:' marker, and nearly every sentence carries distinct information. It is on the longer side for a single tool, but little can be cut without losing the direction, integrity, or prerequisite guarantees.

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 state-mutating tool with no output schema, the description covers what the agent needs: direction, immutability, funding source, prerequisite key binding, and write safety. It leaves return behavior unstated, but that is acceptable given no output schema is declared.

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 83%, so the schema already documents most parameters well. The description reinforces the immutability and payment direction of terms and amount_atomic but adds no new syntactic or semantic detail per parameter. Baseline 3 is appropriate when the schema does the work.

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 with unusual precision ('SELL SIDE. Advertise what you do and what you charge'), and explicitly distinguishes itself from the sibling post_listing by direction of payment. An agent can tell exactly what this does without opening the 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 clear when-to-use context ('here YOU are the one who would be paid') and names the contrasting alternative post_listing. It also states a hard prerequisite, binding a key via bind_key first. It stops short of naming withdraw_offer as the undo path or pointing to offers_guide, so it is strong but not fully exhaustive.

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