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

Annotations already cover the safety profile (readOnlyHint=true, destructiveHint=false, openWorldHint=true), and the description adds real behavioral value on top: 'Message and note bodies are not returned' tells the agent what data is deliberately absent from results, and 'GET /activities' names the underlying operation. Return shape and pagination semantics are left to the schema.

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, both front-loaded with the highest-value information: what the timeline contains and what is withheld. Nothing is redundant or padded, and the result-content caveat is placed where it will be read.

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 14-parameter read-only list tool with no output schema, the description covers the returned fields, the filtering dimensions, and one important content limitation. It stops short of explaining pagination or result ordering, though the schema's page/per descriptions partially cover that.

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% and every one of the 14 parameters carries its own description, so the schema does the heavy lifting. The description's filter list roughly restates those fields (type, contact, property, project, owner, category, date) without adding syntax, defaults, or format guidance beyond it.

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 ('List the activity timeline') and enumerates the activity kinds returned, so an agent knows exactly what the endpoint yields. It does not, however, differentiate itself from the closely related propstack_list_events sibling, leaving potential ambiguity about which list to call for calendar-type items.

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 filter sentence ('Filter by type, contact, property, project, owner, category or date') implies how to narrow results, but there is no explicit when-to-use versus alternatives and no statement of exclusions or prerequisites. Usage is inferable rather than stated.

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