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

Annotations only declare the generic profile (not read-only, open-world, non-idempotent, non-destructive), while the description adds concrete behavior: what the published page collects, that a guest link and a separate organizer results link are returned, and a hard 105-day event-length constraint that would otherwise only surface as a runtime error. It also clarifies the negative scope (no email delivery, no payments), which the annotations cannot express.

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?

Four sentences, front-loaded with the trigger and the produced artifact, then constraints, then exclusions. Nothing is repeated from the schema beyond a brief required-field reminder, and every clause carries decision-relevant information.

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?

An output schema exists, so return values need not be enumerated, yet the description still names the two links an agent must surface to the user. For a twelve-parameter, open-world creation tool, the business constraint (105 days) and the negative scope complete the picture an agent needs before calling.

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 all twelve parameters, including formats and limits, are already documented in the schema. The description only restates that title, start, and time_zone are required, which the required array already conveys. This is the expected baseline when the schema carries the semantics; no meaningful extra meaning is added.

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 pairs a specific verb with a specific artifact: it publishes a shared web page where guests answer Yes/No/Maybe, add plus-ones, and answer an optional multiple-choice question. The outcome (a guest link plus a private organizer link) is stated, making it clearly distinct from update_rsvp_page, show_rsvp_results, and add_rsvp_guests without needing to open any schema.

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?

It opens with an explicit trigger condition ('Use this when the user wants guests to RSVP to an event') and then states what it does not cover: no invitations, emails, reminders, tickets, or payments. Those exclusions route the agent away from a tool that superficially sounds like event management, which is the main ambiguity risk here.

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