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

readOnlyHint=true already declares the safety profile, so the description only adds the API scope and endpoint path. It says nothing about pagination behavior, total counts, or what a page of results contains beyond what the schema and annotations already provide.

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?

Three compact fragments, front-loaded with the action and resource, with zero wasted words. It is terse to the point of omitting useful routing context, which is the only thing keeping it from a 5.

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?

A read-only list tool with a fully documented schema and no output schema; the description gives the resource, its scope, and the endpoint, which is enough to call it correctly. The unresolved question of whether candidate activities are included is the main 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% and the descriptions are detailed (sort example, filter comparison operators, page_size max 100), so the schema carries parameter meaning. The description adds no additional parameter guidance, which is the baseline-3 case.

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 CRM activities") and the parenthetical enumerates what counts as an activity (calls, meetings, notes). It does not differentiate from the closely related sibling traffit_get_candidate_activities, so it falls short of a 5.

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?

There is no when-to-use guidance and no alternatives named. The scope note (clients and contacts) only indirectly hints at how this differs from traffit_get_candidate_activities, leaving the agent to infer which tool to pick.

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