mem_stats

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

Annotations already declare readOnlyHint=true, destructiveHint=false, and idempotentHint=true, so the safety profile is clear. The description adds the useful scope detail that it 'counts the whole store,' but it does not disclose other behavioral traits such as return format or pagination. With annotations covering the core safety aspects, this is adequate but not richer than expected.

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 long, with the primary purpose front-loaded. The first sentence states what the tool does, and the second sentence adds an alternative. Every word earns its place with no fluff or repetition.

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?

This is a simple tool with no parameters and an output schema (not shown but present). The description provides the essential context: aggregate scope, no arguments, and a clear alternative for project-specific counts. Given the low complexity and strong annotations, this is complete enough for an agent to select and invoke the tool correctly.

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 schema fully covers parameter semantics (100% coverage). The description redundantly says 'Takes no arguments,' aligning with the schema. Per the rubric, 0 params earns a baseline of 4, and no additional parameter explanation is needed.

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 uses a specific verb+resource construction: 'Get aggregate memory store statistics.' It clearly distinguishes from siblings by explicitly noting that 'for one project's counts call mem_doctor with that project,' which prevents confusion with similar memory tools.

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 explicit contextual guidance: it states the tool counts the whole store (when to use) and directs users to mem_doctor for project-specific counts (when not to use, with an alternative named). This is a clear and useful usage guideline.

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