get_activity_summary

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

With no annotations provided, the description carries the full behavioral burden. It implicitly characterizes this as a read-only summary and scopes it to 'this machine', which is useful, but it says nothing about permissions, rate limits, result size, or pagination behavior despite exposing a limit parameter.

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: the first front-loads what is returned, the second immediately follows with when to use it. No filler, no redundancy, every clause 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?

There is no output schema, so the description must convey return values, and it does by listing sessions, tool-call counts, files touched, and liveness. Combined with complete schema coverage for the two optional parameters, an agent has what it needs, though scope limits (e.g., how far back the summary reaches) go unstated.

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 description coverage is 100%, so both parameters (limit and session_id) are already documented with defaults and bounds. The description adds no parameter-level detail beyond generically referring to 'sessions', so the baseline 3 applies.

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 the resource (agent sessions on this machine) and enumerates the specific content returned: session counts, tool-call counts, files touched, and liveness. It is concrete enough to distinguish it from a generic status tool, though it doesn't explicitly contrast itself with close siblings like get_files_touched or get_recent_events.

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 gives two explicit use cases: checking what has already been tried before starting work, and answering 'what have you been working on?'. That is clear context for invocation. It stops short of naming alternatives or exclusions (e.g., when to prefer get_recent_events over this), so it doesn't reach a 5.

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