search_index

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

With no annotations, the description carries the full burden and delivers: query semantics (ANDed prefix matches), return shape (folder+uid for get_message, attachments field listing names with content not indexed), self-sync behavior (on start, every 10 min, and before a search if stale >5 min), and an explicit security boundary on untrusted external data. This is unusually rich behavioral context.

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?

It is front-loaded with purpose and sibling preference before semantics, return info, sync, and security. Multiple dense sentences are justified, though the security-boundary sentence is lengthy and could be tightened without losing meaning.

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 tool with no output schema, the description covers what an agent needs: how query terms match, the result shape and follow-up tool (get_message), index freshness, and the security posture. Nothing essential for correct invocation is missing.

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 schema already documents all 10 parameters, making 3 the baseline. The description adds value beyond the schema by explaining the query matching semantics ('rechnung' also finds 'Rechnungen') and clarifying that the attachments field lists names rather than indexable content, though it says little about the metadata filters themselves.

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 names a specific verb (ranked full-text search), the resource (local mail index), and the scope (last ~3 years, excluding Spam/Trash). It explicitly distinguishes itself from the sibling search_messages by stating 'Prefer this over search_messages', so an agent can route without opening either schema.

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?

It clearly points to the alternative ('Prefer this over search_messages') and gives a decisive selection rule. It stops short of stating the inverse condition—when to fall back to search_messages (e.g., mail older than ~3 years or messages in Spam/Trash)—so no explicit exclusion is provided.

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