query

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It explains how to provide the argument but does not disclose what the tool returns, whether it is a read-only operation, error behavior, or side effects. It implies a query/read action but stops short of describing the tool's actual behavior.

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 concise and front-loaded with the key trigger condition. The example adds useful concrete detail without excessive verbosity. It could be slightly tighter, but each sentence contributes to understanding.

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 simple one-parameter tool, the description covers the basic invocation and param provenance. However, since there is no output schema and no annotations, the description should ideally mention what the tool returns or any relevant behavioral outcomes. It is minimally viable but leaves some gaps.

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 schema only defines 'topic' as a required string with no description, so the description must compensate. It does so effectively by explaining how to find the topic (from previous 'discover' messages) and providing a concrete example of a topic string, giving meaning beyond the bare schema.

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: to query the status of a device by providing a topic. It uses a specific verb and resource ('query status' by topic), and the example makes the intent concrete. It does not explicitly differentiate from sibling tools 'discover' and 'publish', though the focus on querying status is distinct enough.

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 explicitly states when to use the tool ('When asked status of a device') and gives a concrete prerequisite: the topic must come from previous messages from the 'discover' tool. It does not explicitly state when not to use it or name alternatives, but the contextual guidance is clear and actionable.

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