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

With no annotations provided, the description carries the full burden of behavioral disclosure. It adds useful context about the journal mode including participant names, which is beyond the schema. However, it does not disclose other behavioral traits such as pagination behavior, default sorting, or that include_deleted is honored, leaving room for ambiguity.

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 description is two concise sentences, front-loaded with the primary action 'List activities', and every word adds value. No unnecessary repetition of schema details.

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?

Given the tool has 8 parameters but no output schema or annotations, the description covers the main use cases (filtering, journal mode) without needing to explain every parameter. The schema handles the remaining details. It stops short of a 5 because it omits mention of pagination or sorting behavior, which could be relevant to an agent.

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 coverage is 100%, providing baseline 3. The description adds meaning by grouping parameters into 'filtered by contact or type' and clarifying that days_back/since trigger a journal mode with participant names, which is not explicitly in the schema. This enhances understanding of how the parameters are intended to be used.

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?

The description clearly states the tool lists activities and specifies optional filters by contact or type, as well as a chronological journal mode with participant names. It distinguishes the core function but does not explicitly compare against related sibling tools like contact_timeline or activity_manage, 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?

The description implies when to use the tool (for listing activities, optionally filtered, or with days_back/since for a journal) but does not provide explicit guidance on when to choose an alternative tool or when not to use this one. No exclusions or alternatives are mentioned.

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