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

Annotations already declare a safe read-only, non-destructive operation, so the bar is lower, and the description adds genuinely new behavioral context: the returned link expires after ten minutes and must not be presented as permanent. It does not discuss batching limits beyond the count or failure modes when a path is invalid.

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?

Three compact sentences that front-load what the tool does, then the qualifying paths, then the expiry caveat. No filler, though the opening sentence is slightly loose in phrasing.

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 an output schema present, return-value detail is unnecessary, and the description still surfaces the critical ephemeral-link warning plus the path provenance rule. Only the absence of any tool-selection framing keeps it from being fully 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 coverage is 100%, so the baseline is 3, but the description adds meaning beyond the schema by stressing that paths must be passed exactly as a meal or food returned them and by tying them to the food-photos/ prefix convention. That reinforces format fidelity the schema states more tersely.

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: retrieve/view saved photos belonging to the person's own foods and meals. It is distinguishable from siblings like get_meal because it acts on photo paths rather than the meal itself, though it never explicitly names an alternative tool.

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 tells the agent which paths qualify (those starting with food-photos/) and that up to six can be passed, which implies usage context. However, it never states when to prefer this over siblings such as get_meal or list_meals, so tool-selection guidance remains implicit.

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