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

Annotations only say readOnlyHint=false and destructiveHint=false; the description adds the material hidden behavior — the file is served from a CDN and emailed to the account owner, i.e. it leaves the conversation. That is exactly the out-of-band side effect an agent needs to know before invoking a non-idempotent export.

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?

Front-loaded with purpose, then the delivery caveat, then routing. Slightly self-referential with 'which is worth leaving in' style asides ('so it leaves the conversation, which is worth mentioning before calling it'), but no sentence is filler.

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?

No output schema exists, and the description compensates by stating what is returned (a filename) plus where the file lives (CDN) and that it is emailed. With zero required params and fully documented schema, nothing an agent needs in order to call it correctly 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% and the nested `range` object already documents `from`/`to` aliases, ISO/epoch formats, and the backend default when omitted. The description adds no parameter-level guidance, so the schema carries the load and the baseline 3 applies.

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 ('Generate a CSV export of campaign performance') and adds the return shape (a filename). It explicitly distinguishes itself from the two nearest siblings, `lead_export` (prospect data) and `analytics_campaign` (inline numbers), so an agent can route correctly without opening a 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?

Gives an explicit when-to-use-each rule: use this for performance numbers as a file, `lead_export` for a file of prospects, `analytics_campaign` to read the numbers in-conversation. It also surfaces a precondition (the export leaves the conversation and is emailed to the account owner) that should be considered before calling.

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