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

Annotations already declare readOnlyHint, openWorldHint and destructiveHint=false, so the safety profile is covered. The description adds genuine context: date-range scoping, that omitting product_id includes every product, and an authentication requirement. It stops short of describing the return shape or pagination, so not 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?

It is only three sentences, but the first and second say the same thing twice ('The figures shown in the Supplier Portal performance view, for a date range' vs 'Returns the figures ... for the range'), which is pure duplication. The useful content (product scoping, auth) is tacked on at the end rather than front-loaded.

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 output schema, the description should help an agent anticipate what comes back, but 'the figures' is never unpacked, so a caller cannot know what metrics or format to expect. Auth and scoping are covered, which keeps it at the minimum-viable level.

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 description's param note ('Without product_id every product is included') merely restates the schema's 'Default: all products.' It adds no syntax or format detail beyond the schema, so the baseline of 3 is correct.

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 clear verb and resource (returns the performance figures from the Supplier Portal performance view) and scopes it to a date range. No sibling tool covers performance/reporting, so it is distinguishable from get_availability, list_bookings, and list_products. The vagueness of 'the figures' keeps it 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 hints at when to use it (date-range performance reporting) and states a prerequisite ('Needs the user's Cotlet API key with access to this app'). It does not name alternatives or say when not to use it, so usage is only implied rather than spelled out.

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