Fastly NGWAF MCP Server

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

With no annotations, the description carries full burden but only states the basic action. It doesn't disclose behavioral traits such as pagination behavior (implied by 'page' and 'limit' params but not explained), rate limits, authentication requirements, or whether it's a read-only operation (though 'List' suggests it). This leaves significant gaps for agent decision-making.

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 with zero waste. It's front-loaded with the core purpose and appropriately sized for a list operation, earning its place without 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 no annotations, no output schema, and 4 parameters, the description is incomplete. It lacks context on return format (e.g., list structure, error handling), usage constraints, or how it fits with siblings like 'list_corps'. For a tool with moderate complexity, this minimal description leaves the agent under-informed.

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 4 parameters. The description adds no additional meaning beyond implying filtering via 'query' and pagination via 'page'/'limit', which are already clear in the schema. 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 'List sites in a corporation' clearly states the verb ('List') and resource ('sites'), with scope ('in a corporation'). It distinguishes from siblings like 'get_site' (singular retrieval) and 'list_corps' (different resource), but doesn't explicitly contrast with 'search_requests' or 'list_events' which might overlap in domain.

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?

No guidance on when to use this tool versus alternatives is provided. It doesn't mention when to choose 'list_sites' over 'get_site' (for single site details) or 'search_requests' (for filtering requests), nor does it specify prerequisites like needing corporation context or authentication.

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