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

Goes well beyond the annotations by disclosing that the call hits a live external provider, that it writes/caches the result on the profile (which explains why readOnlyHint is false despite being a counting operation), and that sizing consumes no credits while contact reveals are metered. The cost model is exactly the kind of non-obvious behavior an agent needs before calling.

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?

Two sentences, no filler: the action and its side effect come first, and the cost guarantee follows as the secondary fact an agent needs. Every clause carries 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?

For a one-parameter tool with no output schema and reasonable annotation coverage, the description covers what happens, where data comes from, what side effect occurs, and the billing implication. It stops short of saying what the response contains (presumably the count) or whether the live re-count is slow or rate-limited.

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?

Only one parameter and schema description coverage is 100%, with the schema already stating 'The numeric ICP ID (from list_icps)'. The description adds no further meaning about the id beyond tying the count to an ICP's targeting criteria, so baseline 3 applies.

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?

States a specific verb (re-counts), resource (prospects matching an ICP's targeting criteria), and data source (live data provider). The caching clause implicitly separates it from a plain cached read like get_audience_size, though no sibling is named explicitly.

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 word 'Re-counts ... against the live data provider' implies this is the refresh/freshness path, so usage is inferable. But there is no explicit when-to-use versus get_audience_size, no statement of when not to call it (e.g. cost of latency), and no prerequisites such as ICP existence or connectivity.

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