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

Annotations dispose of the safety profile (readOnlyHint=false, destructiveHint=false, idempotentHint=true), and the description adds non-obvious context the annotations lack: only provided fields are mutated, and an editor token is required. It does not cover failure modes for a bad containerId, so it stops short of a 5.

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?

Four sentences, front-loaded with the core action, then prerequisites, then the resize special case. Efficient, though the parenthetical about edges at x±width/2 restates what the schema already says and could be trimmed.

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 annotations covering mutability and no output schema to explain, the description supplies what an agent needs: prerequisites, partial-update semantics, and the resize workflow. It lacks any statement about error behaviour or what a successful call returns, which is a minor gap rather than a blocking one.

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 83%, so the schema carries most parameter meaning. The description nonetheless adds real semantics for the resize case — that width/height must be enlarged to fit member nodes and x/y adjusted to keep the container centred over them — which the schema entries only hint at.

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 and resource ('Updates properties of an existing container in a live Trident document') and goes further to name the two behaviours that matter most — partial update and resizing. The 'container' resource cleanly separates it from sibling update_node and update_annotation.

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 routes the agent: 'Use get_document_summary to get all container IDs before calling this', states the auth requirement ('Requires a valid editor access token'), and gives the condition for using the resize path ('whenever you add or move nodes outside a fixed-size container'). When-to-use and prerequisites are both covered.

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