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

The annotations already declare a safe, idempotent, closed-world read with no destruction, so the safety profile is fully covered elsewhere. The description contributes the content scope (counts plus last-changed timestamp), but says nothing about whether counts are global or filtered, caching behavior, or return structure.

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 a single front-loaded sentence with no filler, and the resource and freshness information come first. The trailing 'and when the data last changed' clause is slightly tacked on but still earns its place.

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?

For a parameterless, read-only stats tool with no output schema, the description conveys the two things an agent needs: what is counted and that freshness metadata is included. It could go further by describing the shape of the returned counts (e.g. whether categories and places are separate fields), but nothing essential 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?

The tool takes zero parameters, so the baseline is 4; there is no parameter meaning the description needs to supply. Schema coverage is 100% and the empty schema is consistent with the description's parameter-free nature.

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 verb ('Get') and a specific resource ('number of published quantum companies, places and categories') plus data freshness, which clearly separates it from the sibling list_*/get_listing tools that enumerate records. It stops short of naming those siblings explicitly, so it is clear rather than perfectly differentiated.

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?

Usage is only implied: an agent can infer this tool is for aggregate counts and freshness rather than record retrieval. There is no explicit when-to-use statement, no mention of alternatives like list_products or get_listing, and no stated preconditions.

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