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

With no annotations provided, the description carries the burden of disclosure. It implies a read-only aggregate snapshot by saying 'totals', but it does not explicitly state side-effect-freedom, data freshness, authentication requirements, or response structure. The core behavior is conveyed, but safety and edge behavior are not.

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 sentence that front-loads the resource ('Marketplace totals') and lists all relevant metric groups. There is no filler, repetition, or ambiguity in formatting.

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 lists the key data categories and is sufficient for selecting and invoking the tool. It could be more complete by hinting at the return format or types, but for a zero-input stats endpoint the essential information is present.

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 is nothing for the description to clarify beyond the schema. The description appropriately focuses on the returned metrics rather than invocation inputs, meeting the baseline for parameterless tools.

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 identifies a specific resource ('Marketplace totals') and enumerates the exact metrics returned: agents, open tasks, completed tasks, and credits. It is immediately distinguishable from the sibling mutation tools and from leaderboard, which would be a different aggregate view.

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 choose this tool over alternatives, such as leaderboard or list_tasks, and no exclusion criteria. An agent must infer from the name and wording alone that this is the go-to for high-level marketplace aggregate counts.

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