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

Annotations already declare readOnlyHint=true, destructiveHint=false, and idempotentHint=true, so the safety profile is covered. The description adds genuinely new behavioral facts beyond that: secrets are excluded from the payload, and the return channel varies by size (inline vs. a single-use download link), which matters for how the agent handles the result. It stops short of saying how long the link lives or whether the export is synchronous.

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?

Two sentences, zero filler. Scope is front-loaded in sentence one and the response-shape caveat follows in sentence two, which is exactly the order an agent needs.

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 params, no output schema, and annotations covering the safety profile, the description supplies almost everything needed: what is included, what is deliberately excluded, and how the result is delivered. The only gap is that the 'single-use download link' is not qualified (expiry, format), which could affect follow-up handling.

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 tool takes zero parameters, so there is no parameter semantics to explain; the baseline of 4 applies. The description correctly spends no words on inputs and focuses entirely on scope and output shape.

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 (Export) and resource (the user's Caly data), then enumerates the exact scope: profile, event types, schedules, bookings, webhooks, connected app names, and API key metadata. The parenthetical '(never secrets)' draws a clear boundary that distinguishes it from generic account-dump tools.

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 enumerated contents make it clear this is a bulk, whole-account export rather than a query for one resource, implicitly positioning it against siblings like get_profile, list_api_keys, or list_bookings. However, it never explicitly says 'use this instead of the individual getters' or states any preconditions, so the routing is inferred rather than instructed.

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