Reply in a channel thread

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

Annotations indicate a write operation (readOnlyHint=false) that is not destructive (destructiveHint=false). The description adds that it returns JSON with 'id' and 'webUrl', and specifies content length limit (28000 chars). This provides useful behavioral context beyond the annotations.

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 front-loaded with the primary purpose in the first sentence. It then lists parameters in a structured Args block. While somewhat lengthy due to repetition of schema info, every sentence adds value (e.g., return format). Could be slightly more concise by omitting parameter details already in schema.

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's moderate complexity (5 params, no output schema), the description is fairly complete: it covers core behavior, return format, and content type options. It does not address error handling or permissions, but with annotations and schema coverage, the agent has enough context to use it correctly.

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%, so the schema already documents all parameters. The description's Args section repeats parameter info without adding new meaning (e.g., default content_type, length limits are already in schema). As per guidelines, baseline 3 is appropriate when schema covers everything.

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 action ('Reply') and the resource ('existing top-level channel message', adds to thread). It distinguishes from sibling tools like 'teams_send_channel_message' (which sends a new top-level message) and 'teams_send_chat_message' (chat reply).

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 usage (reply to an existing message) but does not explicitly state when not to use or provide alternatives. It lacks explicit guidance on prerequisites, though the schema parameter descriptions partially cover that. The context is adequate but could be improved with a note like 'use after teams_list_channel_messages to get the message_id'.

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