Send message

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

With no annotations, the description carries full responsibility for disclosing behavioral traits. It only states the basic send action and the reply option, but does not mention potential side effects (e.g., message visibility, permissions, rate limits) or failure behavior. For a mutation tool, this lacks important contextual information.

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 extremely concise, two sentences with no filler. It front-loads the primary action and includes the only optional behavior in a clear, efficient manner. Every word 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 simple send-message tool with 3 fully described parameters and no output schema, the description adequately covers the core functionality and the optional reply. It lacks information about permissions or return values, but given the simplicity and schema coverage, it is complete enough for most use cases.

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?

The schema provides 100% coverage of parameters with clear descriptions, so the baseline is 3. The description adds a small clarification about replyToMessageId ('Optionally reply to an existing message'), but this is mostly redundant with the schema's 'Message ID to reply to'. No significant additional semantic value is provided.

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 'Send a message to a channel', which specifies the verb, resource, and recipient. It also mentions the optional reply functionality, distinguishing it from sibling tools like send_dm. This is precise and unambiguous.

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 use for channel messages by saying 'to a channel', but does not explicitly contrast with send_dm or mention when not to use it. The optional reply behavior is noted, but there are no explicit alternatives or exclusions, leaving the usage context implied rather than stated.

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