Fathom MCP Server

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

Annotations already declare readOnlyHint=true, destructiveHint=false, openWorldHint=true, and idempotentHint=true, covering safety and idempotency. The description adds valuable context beyond annotations: it specifies the analytics scope (participants and recorders), mentions filtering by time range, and describes the return structure (top_participants, domain_breakdown, top_recorders), which is helpful since there's no output schema. No contradiction with annotations.

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 (purpose, Args, Returns, Examples) and efficiently conveys information. However, the Args section slightly repeats schema details without adding new insights, and the purpose statement could be more front-loaded. Overall, it's concise but has minor redundancy.

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 (analytics with filtering), rich annotations, and 100% schema coverage, the description is largely complete. It explains the return values (since no output schema exists) and provides usage examples. However, it lacks explicit guidance on sibling tool differentiation, which slightly reduces completeness for an agent.

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?

Schema description coverage is 100%, so the schema fully documents all parameters. The description adds minimal value beyond the schema: it repeats parameter names and basic purposes in the Args section but doesn't provide additional syntax, constraints, or usage nuances. Baseline 3 is appropriate as the schema does the heavy lifting.

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 analytics about meeting participants and recorders in Fathom' and elaborates with 'analyzes who attends your meetings most frequently and which domains are most common.' It distinguishes from siblings like fathom_get_summary or fathom_meeting_stats by focusing specifically on participant statistics rather than meeting content or general metrics.

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 implied usage through examples (e.g., 'All time stats', 'This quarter'), but lacks explicit guidance on when to use this tool versus alternatives like fathom_meeting_stats or fathom_list_meetings. No clear exclusions or prerequisites are stated, leaving the agent to infer context from the analytics focus.

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