Add image

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

Annotations already declare readOnly=false, destructive=false and openWorld=false, so safety is covered structurally. The description adds the tab-grouping behavior, but says nothing about precedence when both path and dataUrl are supplied, failure modes for invalid paths, or how the image lands on the canvas (returns an id?). Useful but incomplete for a mutation tool.

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 tight sentences: capability and accepted sources first, then placement semantics and the tab-grouping rule. No filler, and the most decision-relevant guidance is front-loaded.

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 3-parameter insertion tool with no output schema, the description covers the input sources and the one enum that matters. The remaining gap — mutual exclusivity of path/dataUrl and what the call returns — is minor but real.

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 coverage is only 33% (path documented, dataUrl limited to a regex pattern, placement limited to an enum with a default). The description compensates by explaining what placement's enum values actually mean in workflow terms, which the schema leaves as bare strings.

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?

Names a specific verb and resource: 'Add a screenshot or image to the canvas', with the accepted input forms (absolute file path or data URL). It does not explicitly distinguish itself from sibling inserters like snipaya_add_shape or snipaya_add_step, so it falls short of the top mark.

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?

Explicitly prescribes when to use placement 'add' (before/after pairs, steps of a flow) and when to use 'new-tab' (only a new, unrelated image), including a hard exclusion: 'never one tab per related image'. This is exactly the when/when-not guidance an agent needs.

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