redis_big_keys

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

With no annotations, the description carries full burden and does an excellent job: it discloses the read-only nature, exact resource limits (10,000 key scan, 200 MEMORY USAGE calls), the avoidance of KEYS *, and the partial-coverage sampling with coveragePct. It also explains the truncation flag, leaving little ambiguity about behavior.

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 well-structured: a one-line summary, a safety paragraph with limits, and an explicitly labeled Args/Returns section. Every sentence contributes useful information without redundancy, making it concise yet complete.

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?

The description explains the return envelope and the meaning of 'truncated', but it does not detail the structure of each element in 'topKeys' (e.g., key name, type, size). Also, 'coveragePct' is mentioned in the safety section but not shown in the example envelope, leaving a minor gap. Still, overall it is quite complete for a sampling tool with no output schema.

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 coverage is 0%, but the description compensates fully by explaining both parameters: 'top' as the number of rows to return with default 20, and 'target' as the Redis target from config with an omit-for-default instruction. This adds exactly the meaning the schema lacks.

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 identifies a read operation that samples big keys using a SCAN budget and returns largest keys first. The '[READ]' prefix and detailed resource-specific actions ('Walks at most 10,000 keys with SCAN and sizes at most 200') distinguish it from sibling monitoring tools like redis_memory_stats.

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?

It provides clear context for production safety by stating that KEYS * is never used and limits are explicit. It implies when to use this tool (sampling big keys) but does not explicitly contrast it with alternatives like redis_memory_pressure_rca or redis_slowlog.

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