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 multiple data types (last session summary, lessons, failures, stats), saves a session start marker for duration computation with session_end, and implies state mutation (saving markers). However, it doesn't mention error handling, rate limits, or authentication needs, which are common gaps.

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 efficiently structured: it front-loads the core purpose and usage rule, then lists return values clearly, and ends with an additional behavioral note about session markers. Every sentence adds essential information without redundancy, making it highly scannable and zero-waste.

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 complexity (session management with multiple return types) and lack of annotations or output schema, the description does well by detailing return values and session marker behavior. However, it doesn't specify the format of returned data (e.g., JSON structure) or error conditions, leaving some gaps for an agent to handle robustly.

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 thoroughly. The description adds minimal value beyond the schema: it mentions 'focus' is used to 'surface relevant lessons at the top,' which slightly elaborates on the schema's 'Used to surface relevant lessons at the top.' This meets the baseline for high schema coverage without significant enhancement.

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's purpose: 'Single-call session briefing' with the specific action 'Call this at the START of every session' and distinguishes it from alternatives ('INSTEAD of multiple separate smart_recall/recall_best_solution calls'). It explicitly names sibling tools it replaces, making the distinction 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 provides explicit usage guidance: 'Call this at the START of every session' and specifies when NOT to use it ('INSTEAD of multiple separate smart_recall/recall_best_solution calls'). It names concrete alternatives and establishes a clear temporal context (session start), leaving no ambiguity about when to invoke this tool.

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