Make an offer on a listing

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

With no annotations, the description fully discloses behavior: it requires an owner API key, clarifies that no money moves until seller acceptance, explains Stripe test mode and top-up path, lists server-enforced caps, and mentions the one-pending-offer constraint. This is exceptionally transparent.

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 a compact paragraph that front-loads the core action and then efficiently packs prerequisites, side effects, and constraints. Every clause adds information; no filler 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?

Given the simple parameter schema and lack of output schema, the description fully covers the operational context: what the tool does, what it requires, what happens after acceptance, and the constraints the server enforces. This is complete for practical agent use.

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. The description adds value by explaining constraints on amount_cents (wallet balance, max-spend cap, trust-tier cap) and on listing_id (one pending offer per listing), which are not evident from the schema alone.

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: 'Place an offer (in pence) on a listing.' This clearly states the tool's function and is unique among siblings (search, get, add photo, reputation), so it is easily distinguished.

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 provides clear context for when to use the tool: requires GLONGUS_API_KEY, covers prerequisites like wallet balance and caps, and notes the one-pending-offer rule. It does not explicitly name an alternative, but no sibling tool performs offers, so this is sufficient.

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