list-chat-messages

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds genuine behavioral value beyond that: the newest-first ordering and, crucially, the disclosure that keyword filtering is not supported server-side — a real limitation an agent would otherwise discover only after a failed call.

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 sentences with zero filler: the core action and ordering are front-loaded, followed by the time-range capability and the keyword-filter caveat. Every sentence earns its place.

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 read-only listing tool with full schema coverage and rich annotations, the description is nearly complete: it covers scope, ordering, filtering, and the biggest behavioral gotcha (no server-side keyword filtering). No output schema exists, and the schema's maxItems description already handles pagination semantics, so little is missing.

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 already documents all six parameters, including the from/to/timeRange semantics and cursor behavior. The description's mention of 'lastModifiedDateTime filter' largely restates what the schema's timeRange description already says, adding little parameter-level meaning beyond that baseline.

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 messages of a chat' — plus the ordering behavior 'newest first'. This distinguishes it from list-chats (lists chats themselves), get-chat-message (single message), and list-channel-messages (channel, not chat, messages), though it doesn't name those siblings explicitly.

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?

Provides clear context for when the tool applies (listing chat messages with an optional time range) and explicitly routes keyword-filtering use cases away: 'Keyword filtering must be done client-side or via search-m365 with entityTypes=["chatMessage"]'. It could additionally point to get-chat-message for single-message retrieval, but the main cross-tool ambiguity is handled.

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