Session Unique Values

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

The description adds behavioral context beyond the readOnlyHint and openWorldHint annotations by stating that the server produces a CSV and optionally includes per-value counts. It does not contradict annotations and provides useful output format information.

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 two sentences with no wasted words. It front-loads the core function and output format in the first sentence and adds optional features and examples in the second. Perfectly concise.

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?

Given the schema coverage and presence of an output schema, the description adequately covers the main use case. However, it could explicitly mention the scope parameter and provide more detail on the query usage to be fully complete.

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 already covers all parameters with full descriptions, so the description does not add significant new meaning. While it reinforces the role of start/end_time and query, it does not explain nuances like scope or include_counts beyond the schema.

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 clearly specifies the action ('Return the distinct values'), the resource ('a single session field'), and constraints ('over a time range'). It also mentions optional per-value counts. This distinguishes it from sibling tools like search-sessions or session-fields, which return different results.

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 provides concrete use cases ('extracting distinct IPs, ports, or other field values matching a query'), but does not explicitly state when not to use this tool or compare it to alternatives. The guidance is helpful but not exhaustive.

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