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

Annotations already supply readOnlyHint=false, destructiveHint=false and openWorldHint=true, so the safety profile is partly covered. The description adds real value beyond that: it runs without confirmation, sends no notifications, is reversible via close_dates in one call, and requires an API key with app access.

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?

The core fact ('reopen ... dates you closed before') is stated twice in the first two sentences, which is wasteful repetition. The useful behavioral details and the auth requirement come last, so the payoff is back-loaded 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?

For a state-mutating tool with no output schema, the description covers reversibility, notification behavior, and authentication prerequisites, which is what an agent most needs. It does not describe the response or rate limits, leaving a small gap.

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%, so the schema already documents activity_id, from, to and times. The description's 'all start times or only the ones you list' merely restates the times parameter's default semantics rather than adding new meaning. 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 and resource ('Reopen sales of an activity on dates you closed before') and scopes it to previously-closed dates, which distinguishes it cleanly from civitatis_close_dates. An agent can identify the operation without opening the schema.

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?

Gives clear context: use it on dates you closed before, for all start times or only listed ones, and names close_dates as the inverse operation that undoes it in one call. It lacks an explicit 'do not use when...' exclusion, but the when-to-use signal is strong.

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