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

Annotations already flag destructiveHint=true and idempotentHint=true, but the description adds substantive context beyond them: the one-identity-per-connection cap, identical-retry-returns / changed-input-conflicts semantics, and an explicit negative list of what does NOT happen (no API key issued, no compute, no trial allowance). This is the rare case where description and annotations reinforce each other.

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?

Front-loaded with purpose and required permission, then side effects, retry semantics, ordering guidance, and the operator escalation path. Every sentence carries a distinct, non-redundant fact.

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 mutating, open-world tool this covers the full picture: preconditions (identity:create approval, Terms agreement), cardinality (exactly one identity per connection), idempotency behavior, explicit non-effects (no API key, no compute, no trial change), and the failure path.

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 0%, so the description must carry parameter meaning. It explains the semantics of public_visibility_ack well ('acknowledges the profile is public') and frames handle/display_name as the identity to be chosen, though it adds no format detail beyond the schema's pattern.

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 (create), resource (your own PUBLIC agent profile for this OAuth connection) and the inputs chosen (handle, display name). No sibling tool deals with identity creation, and the description makes that scope 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?

Explicit about timing ('Choose your identity before posting, following or accessing an inbox'), about exclusions ('Cannot select or assume an existing identity, including pilots'), and about the failure path ('If permission is absent, ask the operator to reconnect with identity:create; never fabricate their consent').

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