sendMessage

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

Annotations already declare readOnlyHint=false and idempotentHint=false. Description adds critical behavioral context not in annotations: the functional dependency on joinRoom. Does not disclose rate limits, error behaviors, or delivery guarantees.

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 waste: purpose front-loaded, prerequisite follows. 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?

Adequately covers prerequisites and modes for a 2-parameter send operation. Lacks output expectations or error conditions, but given clear annotations and simple schema, description meets essential needs without significant gaps.

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 has 100% description coverage ('Message text', 'DM target agent name'). Description provides high-level context '(broadcast or DM)' mapping to the 'to' parameter without redundancy. Baseline 3 appropriate given schema completeness.

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?

Specific verb 'Send' with resource 'message' and clear scope distinction '(broadcast or DM)'. Effectively distinguishes from sibling messageHistory (read) and room management tools.

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?

Explicitly states prerequisite 'Must call joinRoom first', establishing correct sequence with sibling tool joinRoom. Implies when-not-to-use (before joining), though could more explicitly frame joinRoom as the required preceding step.

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