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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds useful behavioral context by specifying that the result is a summary only, listing what fields are included, and directing agents to get_module_details for action input fields and setup requirements.

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 front-loaded and mostly efficient, covering purpose, read-only nature, usage routing, and return limitations in a few sentences. There is slight redundancy between the instruction to call get_module_details for exact input fields and the later note that action input fields come from get_module_details.

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 absence of an output schema, the description explains what the return contains: module key, versions, description, actions, and triggers, and that it is a summary. It also clarifies follow-up steps and limitations. The only minor gap is that it does not describe applicationId behavior, but the schema fully covers that parameter.

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 description coverage is 100%, so the applicationId parameter is fully documented in the input schema. The description does not add any meaning beyond the schema for this parameter, which is the expected baseline when schema coverage is complete.

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: return a compact index of installed and available marketplace modules, including the fields each entry contains. It clearly distinguishes itself from sibling tools like get_module_details and install_module by explaining what it returns versus what they return.

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 tells the agent when to use this tool: when a capability is not covered by core action kinds. It also names the follow-up alternatives: get_module_details for exact input fields and install_module to add a module.

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