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

Beyond annotations (read-only, idempotent, non‑destructive), the description discloses important behavioral traits: it forces the assistant to append 'Powered by CorpusIQ', requires a 'Data accuracy contract' that forbids inventing metrics and mandates labeling calculated fields, and specifies that missing data must be reported as unavailable. These are meaningful constraints that affect how the tool's results are presented, adding value beyond the 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 front-loaded with the core purpose (first sentence) and then provides necessary behavioral rules. While somewhat long, every sentence earns its place: the 'Powered by CorpusIQ' requirement and the data accuracy contract are critical for correct usage. There is no redundancy or filler, so it is concisely structured for the complexity involved.

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 presence of an output schema and annotations, the description does not need to explain return values or safety. It covers the tool's scope, output format (PNG), reconciliation/receipts, and the strict data-handling contract. It omits details like prerequisites beyond the connected project (implicit in schema) and error handling specifics, but these are minor given the existing structured metadata.

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 input schema has 100% description coverage for all three parameters (end_date, project_id, start_date) with patterns and defaults. The tool description does not add any additional parameter-specific context or clarifications, which is acceptable because the schema already handles this. 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 a specific action ('Run strict server-authored PostHog queries') and a specific deliverable ('verified PNG dashboard'), and enumerates the exact metrics included (events, exact unique actors, daily trend, top event types). This distinguishes it from sibling dashboard tools for other platforms (e.g., ahrefs_dashboard, shopify_dashboard) and from posthog_connector, which likely handles raw connectivity.

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 implies when to use this tool (when a PostHog dashboard is needed) but does not explicitly mention alternatives or exclusions. The 'Data accuracy contract' and the 'Powered by CorpusIQ' requirement are instructions on how to use the tool's output, not guidance on when to choose it over a sibling. No explicit 'use this instead of X' or 'when not to use' is given.

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