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

Beyond the annotations, the description discloses replacement semantics, absence of withdraw, selection rules, tie-breaking, second-price clearing behavior, budget capping, and the not_fulfiller error for listing mismatches. These are consequential behaviors for a mutation tool and are not already covered by the structured annotations.

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 front-loaded and every sentence carries relevant information about scope, constraints, winner selection, and next steps. It is a single long paragraph with some run-on phrasing, so it is not maximally concise, but it avoids filler.

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 complex bidding tool with no output schema, the description covers the auction mechanics, eligibility constraints, replacement behavior, pricing outcome, and post-win workflow. An agent has enough context to call the tool correctly and understand what happens after the bid window closes.

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%, so the baseline is 3, but the description adds meaning beyond the schema by explaining the deadline relationship for eta_minutes, the budget ceiling for amount_pence, the fulfilment-key scoping and not_fulfiller refusal for service_listing_id, and the meaning of confidence_bp. It stops short of adding format details, but the added auction semantics are valuable.

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 states a specific verb and resource: submit or replace a sealed bid on an open intent from the seller side. It clearly distinguishes this action from sibling tools such as intents_list_open, services_submit_quote, and the fulfilment tools by naming the intent-bidding context.

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?

It explicitly frames the tool as seller-side bidding on an open intent, explains that one bid per key per intent exists and a second call replaces it, and states there is no withdraw. It also explains the winner flow and points to services_list_my_sales, services_start_work, and services_submit_deliverable for the post-win path.

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