List Surface Elements

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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so safety is covered. The description adds genuine behavioral detail beyond that: bounds are returned both as raw xywh strings and parsed objects, and Y.Text fields are flattened to plain strings — non-obvious serialization behavior an agent would otherwise have to discover.

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 compact sentences, front-loaded with the action and scope before the return-format detail. The bounds/serialization sentence partially duplicates what the output schema likely carries, but it is dense and earns most of its space.

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?

With 100% schema coverage, complete annotations, and an output schema, the description need only cover scope and any surprises. It does both, including the Y.Text serialization caveat and the dual bounds representation. Only pagination or element-count limits for large canvases is arguably missing.

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 baseline applies. The description only restates that filtering is possible by element type or id, without adding syntax, defaults, or the interaction rule when both type and elementId are supplied — which is the one thing the schema leaves ambiguous.

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 gives a specific verb ('List') and resource ('shape/connector/text/group elements on the AFFiNE edgeless canvas surface'), making the operation unambiguous. It does not, however, distinguish itself from the sibling get_edgeless_canvas, which an agent could easily confuse with this tool.

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?

Usage is only implied: the mention of optional filters by element type or id hints at narrowing a canvas read, but there is no explicit statement of when to call this versus get_edgeless_canvas or the add/update/delete_surface_element siblings. The agent must infer the read-only inspection scenario.

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