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

Annotations cover the safety profile (write, non-idempotent, open-world, non-destructive), and the description adds real value beyond them: the set becomes immediately visible/editable for humans in the Screenshot Studio, and it requires an authorized Sonar account or write-scope API key. Auth and side-effect context are disclosed; rate limits or failure 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?

Three short sentences with zero waste, front-loaded with the action and then the prerequisite and constraint. Every sentence carries information an agent needs.

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 non-idempotent write tool with annotations but no output schema, it covers auth requirements, the prerequisite guide, and the human-visible side effect including where studio_url appears. Nothing critical is missing, though return-value detail remains thin.

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 all six parameters (including the screens/template_id exclusivity and the device_size example) are already documented in structured form. The description reinforces authoring the screens array but adds no syntax or format detail beyond the schema, so baseline 3 applies.

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?

Specific verb + resource ("Create an app-store screenshot set for a product") with clear scope. It is readily distinguishable from sibling read/update/delete screenshot tools without opening a schema.

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?

States a prerequisite ("Read sonar_screenshot_layout_guide first, then author the screens array") and the schema documents the screens-vs-template_id choice. It doesn't explicitly say when to prefer sonar_add_screenshot or the update tool instead, so it stops short of full alternative routing.

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