MCP Email Service

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 mentions 'based on local cache data' which provides useful context about the data source, but doesn't describe what 'recent' means (timeframe), whether this is a read-only operation, what permissions are required, or what the output format looks like. For a tool with zero annotation coverage, this leaves significant behavioral 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 a single, efficient sentence that gets straight to the point. Every word earns its place - 'return' (action), 'recent sync activity/health' (what), 'per account' (scope), 'based on local cache data' (source). There's no wasted verbiage or unnecessary elaboration.

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 has no annotations and no output schema, the description provides basic but incomplete context. It covers the core purpose and data source, but doesn't explain what 'activity/health' entails, what timeframe 'recent' covers, or what the return values look like. For a tool with 2 parameters and no structured behavioral hints, this is minimally adequate but has clear 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?

The input schema has 100% description coverage, with both parameters ('account_id' and 'include_stats') well-documented in the schema. The description doesn't add any parameter-specific information beyond what's already in the schema descriptions. According to the scoring rules, when schema_description_coverage is high (>80%), the baseline is 3 even with no param info in the description.

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 with specific verbs ('return recent sync activity/health') and resources ('per account based on local cache data'). It distinguishes from obvious siblings like 'get_sync_health' and 'get_sync_history' by specifying 'recent' and 'based on local cache data', but doesn't explicitly differentiate from all possible alternatives.

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 no guidance on when to use this tool versus alternatives like 'get_sync_health' or 'get_sync_history'. It mentions 'recent' and 'local cache data' which imply some context, but doesn't explicitly state when this tool is preferred or when other tools should be used instead.

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