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

Annotations already establish readOnly, idempotent, non-destructive, closed-world behavior, so the safety profile is covered. The description still adds meaningful context beyond that: the data is 'stored' (i.e., precomputed/cached rather than live-computed) and comes with its own 'calculation time', which tells the agent how to judge freshness — a real behavioral disclosure.

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?

A single front-loaded sentence with no filler. The two facts the agent needs (what is returned, and that a calculation timestamp accompanies it) are both present and neither is padded.

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 an output schema present, the description need not enumerate return fields, and with zero parameters there is no input to explain. The only remaining gap is the vagueness of 'aggregates', which the output schema presumably resolves.

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 nothing for the description to disambiguate; baseline 4 applies. The schema being fully described and parameter-free means no semantic gap remains.

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?

It names a specific verb ('Read') and a resource ('stored public catalogue aggregates and their calculation time'), so the agent knows it is a retrieval of precomputed catalogue data. However, 'aggregates' is left undefined — the agent cannot tell what metrics or dimensions are covered, nor how this differs from sibling tools like getAuctionCatalogue or getPublicListingSourceBySlug.

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?

There is no statement of when to call this versus the many catalogue/listing siblings, and no prerequisites or exclusions. The agent must infer usage purely from the resource noun.

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