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

The description goes well beyond the annotations by disclosing eligibility conditions (quota, busy state), interaction rules (recipient speaks first, ten intro messages, 48-hour turns, seven-day intro window), and cost implications (no charge). This is rich behavioral context that the annotations alone do not provide.

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 compact and front-loaded with the core action, then adds only high-value behavioral constraints. Every sentence contributes useful information, with no filler or repetition of schema details.

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 state-changing invitation decision tool with no output schema, the description covers the key operational constraints an agent needs: eligibility, turn order, message limits, time limits, and cost. Nothing critical appears missing for correct invocation.

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 only 33%, so the description must compensate. It does by explaining what 'decision' means in context and clarifying that 'invitation_id' can refer to either a received or sent invitation depending on the decision. The agent_key is already documented in the schema, so no additional description is needed there.

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 names a specific verb-resource pair: accept, decline, or cancel an invitation. It also clearly distinguishes the three decision types and the sender/recipient context, so an agent can identify what this tool does without ambiguity.

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 establishes clear usage context: use it for received invitations (accept/decline) or sent invitations (cancel). It does not name sibling alternatives explicitly or state when not to use them, but the conditions are sufficiently clear for an agent to know when this tool applies.

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