service_list_endpoints

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

No annotations are provided, so the description carries the full behavioral disclosure burden. It implies a read-only operation with 'List', but never states whether it's non-destructive, what the output format looks like, whether auth/permissions are required, or what 'documented vs implemented' actually distinguishes. For an unannotated tool, these are meaningful gaps.

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?

A single, focused sentence that front-loads the action and the resource. Every word earns its place; there is no filler or redundant phrasing. Appropriate length for a description of a simple list operation.

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?

For an unannotated, no-output-schema list tool, the description is mostly adequate but incomplete. It doesn't describe the response shape (a list of endpoint strings versus objects with methods/properties), which the agent would need to know to use the result. Given the absence of an output schema, the description should have covered this.

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?

The tool takes zero parameters, so there is nothing for the description to explain about parameter usage. Per the rubric, a 0-parameter tool gets a baseline of 4. The description adds no parameter-specific meaning, but that is expected and acceptable here.

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 uses a specific verb ('List') and names the resource ('documented/implemented target service HTTP endpoints exposed by this MCP server'). It is clear about scope, though the qualifier 'documented/implemented' is slightly ambiguous. It distinguishes from most siblings which concern config, health, purge, and connection info, but doesn't explicitly differentiate from service_connection_info, which could overlap.

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 the many siblings (fastly_get_config, service_connection_info, service_health_check, etc.). With 11 sibling tools, an agent has no routing hints to pick this one over alternatives. No when-to-use or when-not-to-use context is provided.

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