get_activity_messages

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

With no annotations, the description carries the full behavioral burden, and it does communicate that this is a read ('Get'). However it says nothing about permissions/auth, ordering, pagination, or whether an activity with no messages errors versus returns empty. For a simple read tool this is acceptable but not rich.

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 purpose is front-loaded in a single clear sentence with zero waste. The Args block is slightly boilerplate but short and not padded, so the definition stays tight.

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 single-parameter read tool with an output schema present, the description covers what it returns (messages/notes/comments) and what input it needs. Return-value detail is correctly left to the output schema, leaving only minor gaps like empty-result behavior.

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 0% and there is one parameter, so the description must compensate. It does label activity_id as 'The Intervals.icu activity ID', adding meaning beyond the bare 'Activity Id' title, but it doesn't specify format (numeric/string) or where the ID comes from.

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 uses a specific verb (Get) plus resource (messages/notes/comments) scoped to 'a specific activity from Intervals.icu', making the operation unambiguous. It does not, however, distinguish this read from the sibling write tool add_activity_message or other activity-detail tools, so it stops 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 purpose implies when you'd use it (fetching notes/comments attached to an activity), but there is no explicit when-to-use vs when-not guidance and no mention of the sibling add_activity_message as the alternative for writing. Usage is inferred rather than stated.

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