Harmonic MCP Server

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

The description adds valuable behavioral context beyond annotations: it explicitly states 'This is a READ operation (does not create data)' (reinforcing readOnlyHint), explains the HTTP 404 behavior with background enrichment, and provides rich details about return data structure. While annotations cover safety (readOnlyHint, destructiveHint) and idempotency, the description adds practical implementation details about response format and error handling.

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 clear sections (What it does, Supported identifiers, Returns, Example, HTTP 404 Note), each earning its place. It's comprehensive yet efficient, with no redundant information. The front-loaded statement clearly establishes the tool's purpose before diving into details.

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 (10 parameters, no output schema), the description provides excellent completeness: it explains what the tool does, how to use parameters, what data returns, includes a detailed example response, and covers error behavior. The annotations provide safety context, and the description fills all remaining gaps without needing an output schema.

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 baseline is 3. The description adds significant value by organizing parameters into 'Supported identifiers' with clear examples and the 'use ONE' constraint, plus explaining the response_format parameter's purpose. It provides semantic grouping and usage guidance that goes beyond the schema's individual parameter descriptions.

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 specific verb ('look up', 'finds and enriches') and resource ('company profile') with explicit scope ('by domain, website URL, or social media URL'). It distinguishes from siblings like harmonic_search_companies by focusing on lookup by identifiers rather than search queries, and from harmonic_get_company by being identifier-based rather than ID-based.

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 clear context for when to use this tool ('by domain, website URL, or social media URL') and mentions 'use ONE' identifier, which helps avoid misuse. However, it doesn't explicitly state when NOT to use it or name specific alternatives among the sibling tools, though the context implies it's for identifier-based lookup versus search-based approaches.

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