cachly-mcp-server

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

With no annotations provided, the description carries full burden and effectively discloses key behaviors: it describes the return format ('values in the same order as the keys array') and handling of missing data ('missing keys are null'). It doesn't cover error cases, performance limits, or auth needs, but provides solid operational context.

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 a single, efficient sentence with zero waste: it front-loads the core action, specifies the technology, and details return behavior. Every part earns its place by adding value, making it highly concise and well-structured.

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 no annotations, no output schema, and 2 parameters with full schema coverage, the description is largely complete for a read operation: it covers purpose, usage hint, and return behavior. It could improve by mentioning error handling or performance limits, but it adequately supports tool selection and invocation.

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 the schema already documents both parameters (instance_id and keys). The description adds no additional parameter details beyond what the schema provides, such as key format constraints or instance_id usage. Baseline 3 is appropriate as the schema does the heavy lifting.

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 specific action ('Retrieve multiple keys'), technology ('using native Redis MGET'), and resource ('keys'), distinguishing it from siblings like cache_get (single key) and cache_mset (setting values). It precisely defines the tool's function without ambiguity.

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 context by specifying 'multiple keys in one round-trip,' suggesting efficiency for batch retrieval versus cache_get for single keys. However, it lacks explicit when-not-to-use guidance or named alternatives, though the distinction from cache_get is clear from the purpose.

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