usage_summary

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

It discloses a key behavioral nuance beyond the annotations: the named memory lists are fenced under project isolation and may be shorter than counts imply. The description also states it is read-only, consistent with annotations but reinforcing the non-destructive nature.

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 concise, with the main content front-loaded in the first sentence. The trailing 'Read-only' slightly redundantly repeats the annotation, but it is a minor redundancy in an otherwise well-structured two-sentence description.

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 has no parameters or output schema, the description provides a thorough inventory of the returned metrics and explains the important fencing caveat. It fully covers what the agent needs to know about the tool's output and behavior.

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 tool has zero parameters, so the baseline is 4. The description adds no parameter-specific details, but none are needed since the schema already shows an empty properties object. The lack of parameters is implicitly supported by the description's focus on global, caller-independent counts.

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 reports a 'roll-up of activity' and enumerates specific metrics (memory/note/session/task counts, retrieval totals, gardener proposals, events by kind). This distinguishes it from sibling tools that handle individual items, making its purpose unambiguous.

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 implies usage for obtaining a machine-wide summary of activity, with the note that counts are identical for every caller suggesting a global overview. It does not explicitly state when to use it over alternatives or provide exclusions, but the context is clear.

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