Session context

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

readOnlyHint=true already establishes the safety profile, and the description adds useful behavioral context by enumerating the returned payload and disclosing the undo contract (one auto undo group per call). It does not say anything about cost, size, or staleness of the returned context, which keeps it out of 5 territory.

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 tight sentences with the payload list front-loaded and the usage instruction following it; no filler. The list of context items is dense but each element earns its place by telling the agent what it gets back.

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 no output schema, the description carries the return-value burden and does so by enumerating the context categories. Combined with a fully documented optional parameter and readOnlyHint, an agent has enough to call it correctly and interpret the result.

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?

The single optional `instance` parameter is fully documented in the schema (100% coverage), including fallback behavior and where to list live instances. The description adds no meaning beyond that, so the 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?

Names the resource (ambient session context) and enumerates the concrete contents: project state, active comp, selected layers, item list, AE.* helpers, ES3 rules, and the undo contract. This clearly distinguishes it from narrower siblings like ae_project_info, ae_comp_info, and ae_layer_info, though it never says so explicitly.

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?

'Call at session start; then rely on ae_do response context' gives a clear lifecycle rule for when to use it and when not to repeat it. It does not name the sibling info tools as alternatives, so it falls short of a full when/when-not/alternative statement.

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