search_emails

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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), so the bar is lower, yet the description adds real behavior: result ordering by UID, exclusive 'before' boundary, calendar-day date semantics, and a security note that returns are untrusted data. It omits return shape and how limit interacts with paging.

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?

Four tight clauses, front-loaded with purpose and scope, then date semantics, then pagination. Nothing is redundant with the name or annotations, and the security warning earns its place.

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?

For a 10-parameter search with no output schema, the description covers ordering, pagination, date boundaries and data trust, which are the highest-risk unknowns. Still missing are return format and the meaning of several filter parameters, so it is strong but not fully self-sufficient.

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 only 30% (only since, before, before_uid documented), so the description must compensate. It clarifies 'AND' combination, date semantics and the exclusive 'before' bound, but leaves to/from/text/limit/mailbox/subject/unread_only unexplained, and it references 'next_before_uid' while the schema parameter is named 'before_uid', a naming mismatch an agent must resolve.

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 ('Search NAVER mail') plus the combination semantics ('AND filters') and ordering ('newest UID first'). It is distinguishable from get_email and list_mailboxes, though it never names those siblings explicitly to reinforce the distinction.

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?

Gives explicit context for the no-filter case ('No filters lists recent mail') and concrete pagination instructions ('Reuse next_before_uid with the same filters for the next page'). It does not name alternatives such as get_email for fetching a single message, so it stops short of full routing guidance.

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