Add item

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

Annotations already declare readOnlyHint=false, idempotentHint=true, and destructiveHint=false, so safety and retry behavior are covered structurally. The description adds useful semantics for `group` (an app-defined lane/section) and `fields` (a JSON object shape), but says nothing about persistence, whether the write is immediately visible, or what happens on duplicate calls beyond what the schema's command_id note already states.

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?

Two short sentences, front-loaded with the core action and then the two most ambiguous parameters. Efficient, though the parameter glosses read more like schema notes than a usage-oriented description.

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?

An output schema exists, so return values need not be described. But for a 6-parameter mutation tool with nested object fields and low schema coverage, the description omits the relationship to apply_data_writes and the meaning of `position`, leaving the agent to infer ordering and persistence behavior.

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 only 17% across 6 parameters, so the description carries real weight, and it does explain two key params: `group` as an app-defined lane and `fields` as a JSON object with an example. It leaves `actor`, `position`, and `collection` undefined beyond their names, so it only partially compensates for the coverage gap.

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?

States a specific verb (Add) and resource (item to a collection), which cleanly separates it from data_update_item, data_move_item, and data_delete_item in the sibling list. It does not, however, explicitly name those siblings or contrast itself with them.

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?

No guidance on when to use this versus data_update_item, data_move_item, or the two-phase apply_data_writes sibling. The presence of apply_data_writes in the sibling set suggests staged writes, but the description never explains whether this call persists immediately or requires a follow-up.

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