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

The annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is fully covered. The description adds that the result is a per-entity-type count plus a last-modified timestamp, which is useful return-value context, but it adds nothing about caching or freshness semantics beyond "when the data last changed".

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?

One sentence of roughly twenty words that leads with the verb and covers both what is counted and the freshness signal. No filler, no repetition of the tool name, nothing to trim.

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?

This tool has zero parameters and no output schema, so the description must carry the return shape, and it does so at a high level: counts for three entity types plus a last-changed timestamp. It is complete enough to call correctly, though it does not say whether the counts are scoped to published items only (it does say "published") or how the timestamp is formatted.

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. The description correctly attributes no input requirements and does not introduce any parameter confusion; the schema and description are consistent on this point.

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 definition uses a specific verb ("Get") and resource (number of published AI agencies, places and categories) plus the last-changed timestamp, so the agent can infer that the tool returns aggregate statistics rather than the listing records themselves. It does not explicitly name the sibling tools such as list_places or list_categories, but the contrast with a list tool is clear enough to be useful.

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?

The description implies this is the tool to call when you want counts or a freshness check rather than actual records. However, it never explicitly says when to use this tool instead of the sibling list_* tools or get_listing, and it states no exclusions or alternative conditions.

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