search_emails

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

With no annotations, the description carries the full burden. It does disclose an important behavior: UIDs are permanent identifiers that don't change when emails are deleted. This adds value beyond the obvious search operation. However, it does not mention that the operation is read-only, or address other behavioral aspects like ordering, pagination, or error scenarios, leaving gaps.

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 concise at two sentences, with the main purpose front-loaded. It avoids verbosity, though the phrase 'using UIDs' is slightly redundant and could be cleared up. The structure is efficient for a search tool.

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 lacking an output schema and annotations, the description provides key information about the return type (UIDs) and their stability, which is crucial for downstream operations. It does not detail return format or pagination, but the parameter schema covers filtering details. Given the tool's moderate complexity (7 parameters), the description is fairly complete but not exhaustive.

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 schema covers 100% of parameters with meaningful descriptions, so the description does not need to explain parameter meanings. It does not add any parameter-specific context beyond what the schema provides, so the baseline of 3 is appropriate.

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 starts with 'Search emails using UIDs with advanced filters,' which clearly identifies the action and resource. However, the phrase 'using UIDs' is slightly ambiguous—it could be interpreted as requiring UIDs as input, but the next sentence clarifies that UIDs are returned. It distinguishes itself from siblings like list_emails by emphasizing advanced filters and the UID return format.

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 implies usage by stating 'Get UIDs from results for subsequent operations,' suggesting when to use this tool (to find emails for later actions). However, it does not explicitly contrast it with sibling tools like list_emails or state when not to use it. The guidance is implicit rather than explicit.

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