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 effectively describes key behaviors: it returns 'saved content or null if not found' (outcome transparency), supports 'glob patterns' (functional capability), and mentions performance optimization ('before doing expensive operations'). However, it doesn't cover aspects like error conditions, rate limits, or authentication needs, which keeps it from a perfect score.

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 appropriately sized and front-loaded: the first sentence states the core purpose, the second explains the return value and primary use case, and the third details advanced functionality (glob patterns). Every sentence adds value with zero waste, making it highly efficient 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 the tool's moderate complexity (2 required parameters, no output schema, no annotations), the description is mostly complete. It covers purpose, usage guidelines, return behavior, and parameter enhancements. However, without annotations or output schema, it could benefit from more detail on error handling or response format, slightly limiting completeness for a retrieval tool.

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 schema description coverage is 100%, so the baseline is 3. The description adds significant value by explaining that the 'key' parameter 'supports glob pattern like "file:*"' and providing examples ('"file:*" matches all file summaries, "arch*" matches architecture-related keys'), which clarifies usage beyond the schema's basic description. However, it doesn't provide similar context for 'instance_id', preventing a perfect score.

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 previously saved context from the cache') and resource ('saved context'), distinguishing it from siblings like cache_get (which appears more generic) and recall_best_solution (which suggests a different retrieval purpose). The verb 'retrieve' is precise and the resource 'saved context' is well-defined.

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 explicitly states when to use this tool ('Use this at the START of any task to check if you already have relevant context cached, before doing expensive operations like reading many files'), providing clear context and purpose. It also distinguishes it from alternatives by implying this is for cached context retrieval rather than other cache operations or learning functions.

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