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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), so the description earns credit for going beyond them: it discloses the 403 failure mode when custom reports are disabled and prescribes the correct recovery (tell the user to contact JobMojito, do not retry). It does not discuss rate limits, caching, or response size, so a 4 rather than 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?

The most important instruction ('Call this first') is front-loaded, which is good, but the description then restates the same content twice — the dataset/dimension/measure enumeration appears in paragraph one and again nearly verbatim in paragraph two. Roughly half the text is redundant, wasting budget on a body that should be tight.

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 no explanation. The description covers scope, the ordering constraint relative to write-ahead report definition tools, and the account-level disabled state — everything an agent needs to call it correctly or route the user appropriately.

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 both merchant_id (scoping/auth caveat) and conversation_id (must be echoed unchanged, do not invent, no parallel calls) are fully documented in the schema. The description adds nothing about parameters, so 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+resource (list report datasets and fields) and immediately scopes it to 'what a custom report can use on this account', which separates it from list_reports, get_report, and preview_report. The enumerated dataset types make the scope concrete.

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 explicit ordering ('Call this first') and a hard precondition ('a report definition may only use ids listed here' / 'ids not listed here are refused'), plus a when-not case: while custom reports are off, the tool fails with 403 and the agent should not retry. This is exactly the when/when-not/alternative guidance the dimension asks for.

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