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

Annotations already declare idempotentHint=true and destructiveHint=false, so the description doesn't need to restate those. It adds useful behavioral context: duplicate names are refused (funnel_exists), exit_page must be last, and the result can be read with funnel_report. This goes beyond the schema and 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 compact and front-loaded: it defines the core concept first, then constraints, then scope, then error behavior, then where to read results. Every sentence adds value and there is no fluff.

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 a creation tool with no output schema, the description covers the essential input semantics, constraints, and error behavior. It doesn't describe the success response format, but that's a minor gap given the tool's simplicity and the reference to funnel_report for reading 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 coverage is only 40%, so the description compensates by explaining the structure of steps with concrete examples and the scope enum values. It also clarifies the duplicate-name behavior. However, it doesn't explain strict_order beyond what the schema says, and site is only referenced via list_sites in the schema, not the description.

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 creates a funnel, defines it as an ordered list of 2+ steps, and provides concrete step type examples. It distinguishes itself from siblings like update_funnel and funnel_report by focusing on creation and referencing the report tool for reading results.

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 gives explicit constraints: exit_page must be last, duplicate names are refused, and scope options are listed. It doesn't explicitly say when to use this vs update_funnel, but the creation context is clear and the duplicate-name refusal provides a clear condition for when not to use it.

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