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

The annotations (readOnlyHint=false, destructiveHint=false) already establish that this is a non-destructive write operation. The description adds no behavioral context beyond the annotations — nothing about partial vs. full updates, return behavior, or effects on omitted fields. It does not contradict the annotations, but it contributes zero additional transparency.

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?

The four-word sentence wastes no words and front-loads the verb. However, the brevity is a symptom of under-specification rather than disciplined editing — there is essentially no substantive content, so it cannot be considered appropriately sized for the communicative job it should perform.

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?

The tool is simple (3 flat parameters, 1 required, no nested objects or enums), the schema documents all parameters, annotations establish the safety profile, and an output schema exists, so much of the burden is already covered by structured data. The remaining gaps — usage context and behavioral specifics — are real but modest, making this minimally viable rather than complete.

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%: id is documented with provenance ('from list_widgets'), and link and text have clear meanings ('New click-through URL', 'New button label'). With the schema carrying full parameter documentation, the baseline of 3 applies; the description neither adds nor detracts.

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 'Update a BUTTON widget' is a near-verbatim restatement of the tool name and title, differing only by emphasizing the word BUTTON, which already appears in the name. It conveys no substantive information about what updating a button widget entails (e.g., changing its label or click-through URL). This is a tautology rather than a clarifying verb+resource statement.

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 is provided for when to use this tool or when to prefer an alternative. The sibling list contains numerous update_*_widget tools (text, image, title, embed, goal, etc.), yet the description offers no criteria for selecting this one, and the only hint of its purpose comes from the schema's parameter names.

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