search_photos

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

Annotations already declare this as read-only, idempotent, and non-destructive. The description adds valuable behavioral context beyond annotations: that the search leverages an on-device index, that filters narrow before ranking, and that natural language phrases work best. This gives the agent a useful model of how the tool behaves internally.

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 efficiently structured: a two-sentence overview followed by a terse Args list. Each line is informative and jargon-free, with no redundant fluff. It earns every word while remaining skimmable.

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?

Despite having 12 parameters and no schema descriptions, the description covers all parameters, provides usage examples, and specifies search behavior. Since an output schema exists, return values need no elaboration. The tool is fully specified for an agent to invoke it 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?

With 0% schema description coverage, the description carries the full burden of parameter documentation. It defines every parameter in plain language, including formats (ISO date, inclusive bounds), allowed values (e.g., screenshots: include/exclude/only), and default behavior (query empty browses by filter). This is exemplary compensation for missing schema descriptions.

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?

Description opens with a specific verb and resource ('Search your entire Apple Photos library') and notes the use of Apple's on-device index. This clearly distinguishes it from sibling tools like look_at_photos or library_stats, which serve different purposes.

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?

Provides concrete usage context: recommends natural visual phrases, explains that filters narrow before ranking, and even describes browsing behavior when query is empty. It does not explicitly exclude alternatives, but the guidance is clear enough for correct selection among siblings.

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