list-channel-messages

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

Annotations already signal read-only and idempotent behavior, and the description adds value by stating the newest-first ordering and the important Graph limitation that server-side filtering is unsupported. This prevents the agent from expecting filter parameters or trying to use this tool for keyword queries.

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 a single front-loaded sentence with a parenthetical that provides the key caveat and routing to the alternative. There is no wasted text or repetition of schema content.

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?

The description plus the well-documented maxItems/cursor parameters gives enough context to invoke the tool correctly, including ordering and truncation continuation. It does not describe the message return shape, but no output schema is present and the list semantics are reasonably clear from the wording.

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 the schema carries the parameter documentation burden. The description does not add parameter-level details beyond the schema, which warrants the baseline score of 3.

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 and resource ('List messages of a team channel') and adds the useful ordering detail 'newest first'. It also explicitly differentiates from the keyword-search sibling by naming search-m365, so an agent can identify what this tool is and is not for.

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?

It clearly states when to use the tool (listing team-channel messages) and gives an explicit alternative for keyword search: 'use search-m365 for keyword search.' It does not enumerate exclusions against other siblings such as list-channel-message-replies, so it stops short of a full 5.

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