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

Annotations already declare readOnlyHint and idempotentHint, but the description adds crucial behavioral context: 'BLOCKS until the user confirms their selection.' It also warns against telling users to drag assets into chat and advises to skip model requests when avatars=0. No contradiction with annotations.

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 lengthy but every sentence serves a purpose: condition, behavior, exclusions, alternatives, and special cases. It is front-loaded with the primary purpose and subsequent guidance is logically organized. It earns its length.

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 no output schema and the tool's complexity, the description is remarkably complete. It covers when to call, blocking behavior, no-UI alternatives, fallback upload procedures, and avatar handling. This is more than sufficient for an agent to decide and invoke the tool correctly.

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 100%, so parameters are already well-documented. The description adds context about expected_types by explaining when to request models (optional, only if specific person is wanted) and mentions 'garment/outfit IDs or textual selectors' which indirectly relates to prompt construction. This goes slightly beyond 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 this is the 'FIRST tool to call for a new photoshoot' when the user hasn't supplied asset IDs or selectors. It specifies the action: 'Opens the MCP app/gallery so the user can choose assets, add them to the Shoot Board, and press Confirm context.' This distinguishes it from sibling tools by explicitly withholding it when a no-UI path can resolve the request.

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 explicit criteria for when to use this tool ('only when the user has not supplied garment/outfit IDs or textual selectors') and when not to use it ('Do not use this when a no-UI path can resolve the request'). It even names alternatives like list_tags/get_items_by_tag/list_garments and upload_garment_from_chat_file, plus avatar fallback options.

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