set_image_alts

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It reveals important non-obvious behavior: 'Groups updates by source so each source is fetched + saved exactly once' and the auto-detection of alt_path. These add significant context beyond what a bare write tool would imply. It does not mention whether it overwrites existing alt text or handle partial failures, but the given details are substantive.

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 description is only two sentences plus a workflow and one clarification. It is front-loaded with the primary purpose, followed by an efficiency note, a concrete workflow, and a key parameter behavior. Every sentence serves a distinct purpose and there is no fluff or repetition of schema content.

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?

Given the tool's moderate complexity (nested items array, multiple sources, grouping behavior), the description covers the essential context: the overall workflow, batching behavior, and alt_path auto-detection. It does not describe return values or error handling, but since there is no output schema, that is partially excused. The description is thorough enough for an agent to use the tool correctly in a typical alt-fill pipeline.

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 input schema already covers all parameters with descriptions, giving a baseline of 3. The description adds meaningful semantics beyond the schema, particularly for alt_path: 'If alt_path is omitted, it is auto-detected via the same probe used by list_image_elements.' It also clarifies the grouping of items by source, which is not explicit in the schema.

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 clearly states the tool's function: 'Batch-write alt text for image elements across pages + global sources.' It uses a specific verb (write), identifies the resource (alt text for image elements), and explicitly distinguishes its batch scope from single-entity tools like update_page_element. It also implies its position in the workflow, making it unambiguous.

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?

The description provides a clear workflow: list_image_elements → read_image → describe → set_image_alts(items), which tells the agent when to invoke this tool (after descriptions are ready) and how it fits with sibling tools. It also notes that updates are grouped by source, implying the benefit over per-source updates. However, it does not explicitly state when NOT to use it or name alternative tools for single updates.

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