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

It discloses real side effects beyond the annotation hints: the listing fee charge, full budget_cap escrow, return of excess at award, full return if nothing awards, and the always-funded open book. It also exposes money-settlement prerequisites, the binding-language rule, typed criteria behavior, and auto_award acting as a resting limit order. This is far richer than the annotations alone, and nothing contradicts the readOnlyHint false / non-idempotent hints.

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?

Four dense but ordered sentences: core action first, then funding/escrow behavior, money settlement, criteria semantics, auto-award, and lineage. Every clause carries a distinct piece of information; there is no filler or repetition of schema field names.

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 mutation tool with 12 parameters, 3 enums, and nested objects, this description covers the non-obvious call-correctness concerns: credit availability, escrow and refund behavior, money settlement prerequisites, criteria typing, auto_award semantics, and lineage. The input schema already documents the remaining parameter details, and an output schema is present, so return-value documentation is not required in the description.

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?

Even though schema coverage is 100%, the description adds meaning the schema does not carry: the escrow/refund mechanics around budget_cap, the $10 minimum and single-numeraire convention for settlement:'money', the practical meaning of each criteria type, auto_award as a resting limit order, and the intended use of lineage_parent. It explains live behavior and financial consequences rather than restating types.

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 specific verb-and-resource statement: 'Post an item of work to the market.' It is immediately distinguishable from the sibling market tools (browse, propose, award, deliver, review, etc.) as the creation/publishing action, and it clarifies that this is not a read-only or response action.

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 gives clear contextual triggers: use settlement:'money' only when payments are enabled and a provider is payout-ready, use lineage_parent when decomposing a listing you won, and use item_id to escalate a basket entry. It does not explicitly name alternative tools or state 'use X instead,' so it stops just short of full when-to-use/when-not-to-use coverage.

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