get_cache_overview

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

With no annotations, the description discloses important behavior: the tool never reads cached data, TLS is required when transit encryption is on (rediss://), and a costSignal note appears for clusters with over 3 nodes. These details go beyond the basic return type and help the agent understand side effects and security implications.

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 four focused sentences: return contents, usage timing/security note, data exclusion, and cost note. Every sentence adds distinct value, with essential info front-loaded.

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 single-parameter read-only overview tool with no output schema, the description provides ample context: what is returned, when to use it, what it excludes, and a behavioral quirk (costSignal). Combined with the schema's maxAgeSeconds explanation, there are no significant gaps.

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 100% with a rich description for maxAgeSeconds (advisory behavior, dataHealth, infrawise analyze refresh). The tool description adds no parameter-specific details, but the baseline of 3 applies because the schema handles the parameter semantics effectively.

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 uses the specific verb 'Returns' with the resource 'all ElastiCache clusters' and enumerates the fields (engine, version, node type, etc.), distinguishing it from sibling get_* overview tools. It clearly identifies the tool's scope and function.

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 gives explicit use cases ('Call this before writing cache client code... or when reviewing cache availability and security posture') and an exclusion ('Cached data is never read or included'), but does not name alternative sibling tools. This provides strong context without explicit alternatives.

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