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

Annotations only supply destructiveHint=true and a title, so the description does meaningful work: it discloses the return value ('Returns the new id') and the Neon endpoint (POST /activities), plus the lookup dependencies for derived ids. It omits any mention of permission requirements or side effects on linked accounts/users, which keeps it short of a 5.

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?

Three tightly packed sentences that front-load the action and the required inputs, then the return value and endpoint. No filler, no restated title.

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?

With no output schema, the description correctly states the return value (the new id) and enumerates the required inputs and id-lookup helpers, so an agent can construct a valid call. Minor gaps remain around linking semantics for account_ids/system_user_ids, but nothing essential is missing.

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 already documents all 11 parameters including the timezone/status lookup hints. The description largely restates required fields and adds no format or validation detail beyond what the schema provides, which is the baseline-3 case.

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?

States a specific verb and resource ('Create an activity') and clarifies the two modes: logging a constituent interaction or scheduling a task. This clearly distinguishes it from siblings like neon_get_activity, neon_update_activity, and neon_create_account.

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?

Explains the prerequisites for a successful call (subject, start date, time zone id, status id, priority) and routes the agent to neon_list_properties for the timezone and status enumerations. It does not explicitly say when to prefer this over neon_update_activity, but the create/update split is unambiguous from the verb.

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