withings-mcp

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 effectively describes key behaviors: caching behavior (local cache unless live=True), API limitations (max 7 days for detail mode), data sources (API vs cache), and operational constraints (detail=True always fetches live). It doesn't mention error conditions or rate limits, but provides substantial behavioral context for a read-only data retrieval tool.

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 and appropriately sized. It begins with the core purpose, then explains the two operational modes, documents parameters with clear explanations, mentions return behavior, and ends with a sibling tool distinction. Every sentence adds value, with no redundant information. The parameter documentation is particularly efficient in explaining interactions between parameters.

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's complexity (two operational modes, caching behavior, parameter interactions) and the presence of an output schema (which handles return value documentation), the description is complete. It covers purpose, usage guidelines, behavioral traits, parameter semantics, and sibling differentiation. The output schema existence means the description doesn't need to explain return values, allowing it to focus on operational context.

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?

With 0% schema description coverage, the description fully compensates by providing comprehensive parameter semantics. It explains all four parameters: start_date (formats and defaults), end_date (format and default), detail (effect on data type and fetching behavior), and live (interaction with detail mode). The description adds crucial meaning beyond the bare schema, including format examples, defaults, and parameter interactions.

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: 'Get sleep data (summaries or detailed phases).' It specifies the exact resource (sleep data) and distinguishes between two operational modes. It also explicitly differentiates from sibling tools by stating 'Not for body composition -- use withings_get_body instead,' making it clear how this tool differs from 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 explicit guidance on when to use different modes: summary mode for nightly totals (default) and detail mode for minute-by-minute phases. It specifies when live fetching occurs (always for detail, optional for summary) and mentions API limitations (max 7 days for detail). It also directs users to alternative tools for related but different data ('Not for body composition -- use withings_get_body instead').

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