mcp-southwest

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It describes a read-only comparison operation but doesn't mention any behavioral traits like rate limits, authentication requirements, response format, or error conditions. For a tool with 5 parameters and no annotations, this leaves significant gaps in understanding how the tool behaves.

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 a single, efficient sentence that front-loads the core purpose without unnecessary words. It directly states what the tool does (compare fare classes) and includes key details (specific classes, prices, benefits, route) in a compact format. Every element earns its place.

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 complexity of a fare comparison tool with 5 parameters, no annotations, and no output schema, the description is incomplete. It lacks information on behavioral aspects, usage context, and output format. The agent cannot fully understand how to use this tool effectively without guessing about its behavior and results.

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 80%, so the schema documents most parameters well. The description adds minimal value beyond the schema by implying the tool compares fares across all Southwest classes, but it doesn't explain parameter interactions or provide additional context like how 'passengers' affects pricing or what 'benefits' entail. With high schema coverage, the baseline of 3 is appropriate.

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: comparing Southwest fare classes with prices and benefits for a route. It specifies the exact fare classes (Wanna Get Away, Wanna Get Away+, Anytime, Business Select) and mentions both prices and benefits. However, it doesn't explicitly differentiate from sibling tools like 'search_flights' or 'get_flight_details', which might also provide fare information.

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 no guidance on when to use this tool versus alternatives. It doesn't mention prerequisites, exclusions, or how it differs from sibling tools such as 'search_flights' or 'get_flight_details'. The agent must infer usage from the purpose alone, which is insufficient for optimal tool selection.

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