recent_sessions

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It indicates this is a read-only operation ('View summary') but doesn't specify authentication requirements, rate limits, pagination behavior, or what happens when no sessions exist. The description is minimal and lacks important operational context that would help an agent use the tool effectively.

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 perfectly concise with two sentences that each earn their place. The first sentence states the core functionality, and the second provides valuable context about when the tool is useful. There's no wasted language or redundancy.

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 tool's simple nature (one optional parameter, output schema exists), the description is reasonably complete. The output schema will document return values, so the description doesn't need to explain them. However, for a tool with no annotations, more behavioral context would be beneficial to fully understand operational constraints and expectations.

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 description mentions no parameters, and the input schema has only one optional parameter ('limit') with 0% schema description coverage. Since there are effectively 0 parameters described in either the schema or description, the baseline score is 4. The description doesn't need to compensate for missing parameter documentation since no parameters are essential for tool operation.

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 states the tool's purpose: 'View summary of recent sessions' with specific details about what information is provided (start time, end time, tool call count). It distinguishes itself from sibling tools by focusing on session summaries rather than memory management, document processing, or other functions. However, it doesn't explicitly differentiate from potential similar session-related tools like 'session_interactions' or 'session_prime'.

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 implied usage context by stating it's 'useful for understanding usage patterns over time,' suggesting when this tool would be appropriate. However, it doesn't explicitly state when to use this tool versus alternatives like 'session_interactions' or 'session_prime' (both sibling tools), nor does it mention any prerequisites or exclusions for usage.

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