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

Since no annotations are provided, the description carries the full burden. It discloses that the tool returns catalogue, live stats, and a full order ledger, and that every purchase is public. This gives some behavioral context but does not say if the tool is read-only, whether there are any rate limits, or how results are structured. It does not contradict annotations (none exist), but for a read-only market listing, these gaps are minor.

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 single, dense sentence that front-loads the core purpose (Sentinel Market) and immediately states what it returns. It has no filler, is easy to scan, and every phrase adds value. The structure is optimal for a short description.

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 tool has no parameters and no output schema, the description sufficiently covers what an agent needs to know: it returns catalogue, stats, and a public ledger. It doesn't explain the exact format of those results, but without an output schema, that's not strictly required. The description is complete for a simple listing tool of moderate complexity.

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?

The tool has zero parameters, so there are no parameter semantics to explain. The schema coverage is effectively 100% (empty object), and the description does not need to add parameter details. The baseline for 0 parameters is 4, and since nothing is omitted, it appropriately scores 4.

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 clearly states the tool's purpose: it is a market for machine-readable data services sold agent-to-agent, returning a catalogue, live stats, and a full order ledger. It uses specific verbs and a distinct domain (agent-to-agent data services), which differentiates it from generic market tools like commodity_markets or service_market. It is not a tautology, though it does not explicitly contrast with siblings.

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 no guidance on when to use this tool versus alternative markets (e.g., commodity_markets, service_market). It doesn't state any preconditions or context that would help an agent decide to pick sentinel_market over its siblings. The description implies it for data services, but no explicit when-to-use or exclusions are given.

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