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

No annotations are provided, so the description carries the full transparency burden. It clearly states 'Read-only — cached ~24h server-side,' disclosing the operation's safety profile and caching behavior. It further explains the return behavior: 'Returns the full contract JSON, or a single section when section is provided,' and notes the token-saving benefit of using the section parameter. While not exhaustive (e.g., error handling isn't mentioned), the description provides substantial behavioral context.

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 front-loaded with the core purpose and then systematically covers usage, exclusions, read-only status, return behavior, and parameter guidance. Each of the five sentences provides distinct value without redundancy. The structure is logical and easy to parse, even at length.

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?

The tool is simple (one optional parameter, no output schema), and the description fully covers the essential context: purpose, contents, usage, alternatives, safety (read-only, caching), and return format. It also enumerates the available sections in the schema. Given the tool's low complexity, the description is complete and leaves no major 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 already provides 100% coverage with a description for the 'section' property listing valid values. The description adds practical meaning by giving an example ('e.g. motion for just the motion tokens') and explaining the trade-off ('saves tokens when you only need one dimension'). This goes beyond the schema doc and helps the agent decide when to use the parameter.

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 'Get' and identifies a clear resource: 'the Designesy design-system contract.' It lists the contract's contents (tokens, motion, acoustic, takt, cadence, typography, components, verification rules) and distinguishes it from siblings by naming designesy_score and designesy_skill_md as alternatives. This makes it unambiguous what the tool does.

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 explicitly states when to use: 'when you need the actual contract values... to author, check, or bind a design.' It also provides when-not-to-use scenarios with named alternatives: 'for a pass/fail score of a live site, use designesy_score; for an agent-skill-format export, use designesy_skill_md.' This is exemplary usage guidance.

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