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

Annotations already carry readOnlyHint=true, and the description restates 'read_only' (redundant), but it adds genuinely new context: that referrer_id must be a workspace member with the SUPER_CONNECTOR role, that the id filters are optional, and that workspace_id/user_id come from request headers rather than parameters. That header-injection note is valuable since it explains why those fields are absent from the schema.

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 summary sentence followed by clearly labeled 'Use when' and 'Behavior' blocks. Every sentence carries routing or constraint information with no filler.

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, so the return values need not be spelled out, and the description sensibly only names the returned type. Usage, routing, and auth context are covered; the only shortfall is the undefined target_id semantics.

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 0%, so the description must compensate. It clarifies that referrer_id/requester_id are optional filters and that referrer_id requires the SUPER_CONNECTOR role, but it never defines what a target_id actually is, leaving the primary keying parameter ambiguous.

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 (Get) plus resource (current state of a referrer request) and the keying parameter (target_id), and further narrows it against siblings via 'Prefer GetReferrerRequestForReferrerById'. An agent can distinguish it from the intro_request and send_state_change_event siblings without opening schemas.

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 when-to-use ('before SendStateChangeEvent when you need to check current state and do not have referrer_request_id') and names the preferred alternative plus the condition that selects it. Nothing is left to inference.

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