Nanostores MCP

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

The annotations already declare readOnlyHint=true and idempotentHint=true, so the agent knows this is a safe, repeatable read operation. The description adds valuable context about what gets searched (guides, API references, best practices) and the relationship to other resources (nanostores://docs/page/{id}), which goes beyond what annotations provide. It doesn't mention rate limits or authentication needs, but with good annotation coverage, this is sufficient.

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 efficiently structured with zero waste: it starts with the core purpose, explains parameter usage with clear examples, and provides an alternative for related functionality. Every sentence earns its place by adding practical guidance. The example format is particularly helpful without being verbose.

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 moderate complexity, rich annotations (readOnlyHint, idempotentHint), 100% schema coverage, and the presence of an output schema, the description is complete enough. It covers the purpose, usage guidelines, parameter interactions, and relationship to other resources without needing to explain return values (handled by output schema) or repeat what annotations already declare.

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 100% schema description coverage, the input schema already documents all four parameters thoroughly. The description adds some semantic context about how parameters interact (query required unless storeKind provided, combining both for targeted search) and provides concrete examples, but doesn't add significant meaning beyond what's in the schema descriptions. The baseline of 3 is appropriate when schema does most of the work.

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 ('Find', 'Search') and resources ('Nanostores documentation', 'guides, API references, and best practices'). It distinguishes this search tool from siblings like nanostores_clear_cache or nanostores_store_summary by focusing on documentation retrieval rather than runtime operations or analysis.

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 this tool versus alternatives: it specifies to use nanostores://docs/page/{id} for reading full page content after finding relevant pages. It also explains how to combine parameters effectively with clear examples, making it easy to understand appropriate usage scenarios.

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