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

No annotations are provided, so the description bears the full burden of behavioral disclosure. It states the tool shows conversion rates and requires PostHog connectivity, but does not disclose whether the tool is read-only, whether it requires specific permissions, what happens if events are missing, or how results are structured (e.g., percentages, counts). The behavior is partially described but lacks depth.

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 concise at two sentences. The first sentence defines the action and output, the second adds a critical prerequisite. Every sentence earns its place without redundancy. It is front-loaded with the primary purpose.

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 output schema, the description should ideally explain the return format. It says 'Shows step-by-step conversion rates' but lacks detail on whether returns are percentages, counts, or ordered steps. The tool has 5 parameters and moderate complexity; the description covers core functionality but omits output specifics and usage constraints (e.g., minimum 2 events noted in schema but not in description). Completeness is adequate but not comprehensive.

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 baseline is 3. The description does not add significant meaning beyond the schema; it provides an example of steps ('signup → onboard → purchase') but does not elaborate on parameter constraints, formats, or relationships. The schema already adequately defines each parameter, so the description adds marginal value.

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 builds and runs funnel analysis, showing step-by-step conversion rates with an example (signup→onboard→purchase). This distinguishes it from sibling tools like posthog_query_trends (trends) and posthog_hogql (raw SQL). The verb 'build and run' plus resource 'funnel analysis' makes the purpose specific and unambiguous.

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 mentions the prerequisite 'Only works if PostHog is connected,' which is useful context. However, it does not explicitly specify when to use this tool over alternatives like posthog_query_trends or posthog_list_events, nor does it provide when-not-to-use guidance. The usage is implied by the tool's specific function, but explicit differentiation is missing.

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