AWS MCP Server

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

No annotations provided, so description carries full burden. It discloses return contents (engine, node type, status, endpoint, configuration) which is valuable, but omits safety declarations (read-only vs destructive), pagination behavior, or permission requirements.

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?

Two sentences with zero waste: first defines the operation and resource, second defines the return payload. Appropriately front-loaded and scannable.

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 5 optional, well-documented parameters and no output schema, the description adequately compensates by listing return fields. Missing only minor behavioral context (permissions, rate limits) for a complete picture.

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%, establishing baseline 3. The description does not augment parameter semantics (e.g., explaining that cache_cluster_id filters to a single cluster, or that max_records handles pagination).

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?

Specific verb 'Describe' + resource 'ElastiCache clusters' with scope '(Redis/Memcached)'. The description clearly targets provisioned cache clusters, implicitly distinguishing from siblings handling replication groups, serverless caches, or events by specifying the exact resource type.

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?

Mentions supported engines (Redis/Memcached) providing implied scope guidance, but lacks explicit 'when to use vs alternatives' guidance. Does not clarify when to use this versus aws_elasticache_describe_replication_groups for clustered Redis setups.

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