email_search

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

No annotations are provided, so the description carries the full burden. It usefully discloses that results are compact by default and that returnBody=true is needed for full bodies, which is valuable behavioral context. However, it does not mention anything about permission requirements, whether the operation is read-only (though 'search' implies non-mutating), pagination behavior, or what fields appear in results.

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?

Two sentences, zero wasted words. The first sentence states the purpose, the second delivers the critical behavioral note about returnBody and context savings. Exceptionally efficient and front-loaded with the most important information.

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?

This is a 14-parameter search tool with no annotations, no output schema, and 0% schema coverage. The description is far too brief for the tool's complexity. It fails to explain date parameter formats, whether multiple filters combine, unreadOnly/starredOnly/hasAttachment semantics, folder/accountId relationships, or what 'compact results' actually contain. A more complex tool with this little documentation is risky for agents to use 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 0%, so the description must compensate. The description explains returnBody's effect on output, which is the most valuable param hint. However, it doesn't clarify semantics for since/before (date formats?), to/from/subject/body (exact match vs contains?), filter combinations, or whether limit defaults apply. With 14 parameters and 0% coverage, more compensation was needed.

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 states 'Search emails with filters,' which is a clear verb+resource purpose. It distinguishes reasonably from siblings like email_send, email_delete, etc. However, it could better distinguish from email_get_thread and email_get, which are also read operations, and from knowledge_search which might overlap with search semantics.

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 gives good behavioral context (compact vs full results, returnBody flag) but does not explicitly state when to use this vs email_get, email_get_thread, or other search alternatives. No exclusions or alternative tool names are mentioned, leaving some ambiguity about which email retrieval tool to choose.

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