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

Annotations already declare readOnlyHint=false, destructiveHint=false, and idempotentHint=true. The description adds behavioral context: 'Changes apply immediately', 'Response cache is currently fixed at 30 minutes', and the constraint 'Specify exactly one of maxAgeMs, maxAgeMinutes, or maxAgeHours'. This goes beyond the annotations and helps the agent understand side effects and constraints. No contradiction with annotations.

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 with sections (Advantages, Parameters, Returns, Related Tools, Notes) and front-loaded with a clear summary. Some marketing language like '⚙️ Configure cache retention times to optimize for your workflow' is slightly fluffy, but the core content is relevant and organized, making it easy to scan.

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 there is no output schema, the description lists expected returns ('Tool execution results', 'Results per cache type with human-readable durations', 'Timestamp of configuration change'). It also covers constraints (response cache fixed, minimum duration) and relationships. Everything an agent needs to configure cache retention correctly is present.

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 0%, so the description must fully explain parameters. It does: cacheType (with enum values), maxAgeMs, maxAgeMinutes, maxAgeHours, and the note about exactly one and minimum 1000ms. This completely compensates for the lack of schema descriptions, making parameter usage unambiguous.

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: 'Configure cache retention times' and 'Fine-tune cache retention policies for simulator, project, and response caches.' It is specific about the verb (configure/fine-tune) and the resource (cache retention). It distinguishes itself from siblings via the Related Tools section (cache-get-config, cache-get-stats, cache-clear), making clear this is the setter.

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?

Provides guidance on when to use: 'Optimize for development workflows (longer cache = faster repeated operations)' and 'Optimize for CI/CD environments (shorter cache = fresher data)'. It also lists Related Tools like cache-get-config and cache-get-stats, giving clear alternatives. However, it does not explicitly state when not to use it or contrast with each sibling, so it's not a full 5.

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