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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered; the description adds meaningful extras beyond that — the data source is the Performance dashboard and it requires the user's Cotlet API key with app access. It says nothing about rate limits or result freshness, but the added auth/data-source context is genuinely useful.

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 returned-metrics list is front-loaded and easy to scan, but the second sentence largely restates the first ('Returns the figures the Performance dashboard shows for one course: revenue, new enrollments and average rating'), duplicating content without adding 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?

There is no output schema, so the description usefully enumerates the returned metrics (revenue, new enrollments, average rating) and discloses the auth prerequisite. For a two-parameter read tool with annotations covering safety, this is nearly sufficient, though it omits any note on whether the numbers are period-bucketed or cumulative.

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%: the period enum values and default are documented in the schema, and course_id points to list_courses. The description only restates 'over a period' without adding format or interpretation guidance, so the schema does the heavy lifting — baseline 3.

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 names a specific resource (one course's revenue, enrollments and rating over a period) and a specific verb/action, and the phrase 'for one course' scopes it distinctly from aggregate reporting. It never names the closest sibling (udemy_get_revenue_report) or clarifies the contrast explicitly, so it falls short of a 5.

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 gives clear usage context: 'Use it for a weekly or monthly check on a single course,' which tells the agent the intended granularity and cadence. It offers no when-not-to-use condition and does not name the alternative tool for portfolio-wide revenue, so it stops short of explicit alternatives.

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