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

Annotations already declare readOnly=false, idempotent=false, and destructive=false. The description adds genuinely useful behavior beyond that: the invitation is single-use, and acceptance happens out-of-band when the recipient opens the shared URL. This meaningfully enriches the non-idempotent, non-destructive profile the annotations only hint at.

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 tight sentences, front-loading the trigger condition before the mechanism. No filler, though the first sentence is phrased as a condition rather than a direct purpose statement, slightly softening the lead.

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?

An output schema exists (returning the invite URL is referenced but not required to be explained), and annotations cover the safety profile, so the description only needs to supply the when and the acceptance flow — both present. A brief note on whether an existing connection blocks a re-invite would make it fully complete.

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 both contact_id and the nested capabilities flags are already documented in the schema. The description adds nothing about parameter meaning or the on/ask/off semantics, so the baseline 3 applies.

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 ('Creates a single-use invitation') scoped to connecting with someone on the ppl network for agent-to-agent messaging. An agent can easily distinguish it from siblings like connections.accept or circles.invites.create.

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?

Gives a clear triggering condition ('When the human wants to connect with someone on the ppl network') and explains the follow-up flow (share URL, other person accepts). It stops short of naming the complementary sibling (connections.accept) that closes the loop, so it's strong but not fully alternative-aware.

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