cachly-mcp-server

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 clearly describes the return behavior ('Returns null on cache miss') and storage location, which is valuable. However, it doesn't mention performance characteristics, size limitations, or whether this operation is idempotent or has side effects.

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 extremely concise (two sentences) and front-loaded with the core functionality. Every word earns its place: the first sentence defines the operation and return format, the second specifies error conditions and storage location. No wasted words or redundant information.

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?

For a read-only retrieval tool with no output schema, the description provides good coverage of what the tool does, how it behaves on cache miss, and where data is stored. However, without annotations or output schema, it could benefit from mentioning the expected format of the 'ordered list of string chunks' or any limitations on stream size.

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 input schema has 100% description coverage, providing clear documentation for both parameters. The description doesn't add any additional parameter information beyond what's in the schema, but with complete schema coverage, the baseline score of 3 is appropriate as the schema already 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'), resource ('previously cached stream'), and format ('ordered list of string chunks'). It distinguishes from sibling tools like cache_get (general cache retrieval) and cache_stream_set (setting stream data) by focusing on stream-specific retrieval with chunked output.

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 clear context about when to use this tool (retrieving cached streams) and implicitly distinguishes it from cache_get by mentioning the stream-specific storage format ('cachly:stream:{key}'). However, it doesn't explicitly state when NOT to use it or name specific alternatives like cache_get for non-stream data.

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