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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds 'Scope: employee' and the underlying endpoint, which is genuinely useful permission/routing context, but it says nothing about pagination defaults, ordering, or how much history is returned by default — details an agent would want when the result set can be large.

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 short sentences: the core action with concrete examples first, then scope and endpoint. Nothing is padded and the most decision-relevant information is 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?

No output schema exists, but the parenthetical ('notes, stage moves, mails') gives the agent a usable picture of the return content, and pagination controls are fully described in the schema. Only minor gaps remain, such as default ordering and whether the list is truncated.

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 page, page_size, sort, filter, and candidate_id are all documented in the schema; baseline 3 applies. The description adds no parameter-level meaning, and the endpoint string 'GET /employees/{id}/activities' arguably muddies things by referring to an employee path while the required parameter is candidate_id.

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 history of one candidate') and enumerates concrete content types (notes, stage moves, mails), which distinguishes it from siblings like traffit_get_candidate_files, traffit_get_candidate_tags, and traffit_get_candidate_jobs. It does not explicitly name those siblings, but the examples make the boundary clear enough to choose correctly.

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 implied by 'activity history of one candidate' but there is no explicit when-to-use or when-not guidance, and no comparison against the many sibling candidate-scoped getters. The agent must infer that this is the tool for timeline/audit data rather than files, jobs, or tags.

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