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

Annotations declare a non-read-only, non-idempotent, non-destructive call but say nothing specific, so the description carries real weight: it discloses the once-per-account gating condition, the zero-quota cost, and a PII exclusion ('Leave out personal data'). It does not say what happens on a repeat call (relevant given idempotentHint=false) or what the call returns, which keeps it short of a 5.

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?

Five short sentences, no filler, and the most consequential fact — that nothing else works until this is called — is front-loaded. Every sentence carries a distinct instruction (gate, content, ask-don't-guess, cost, PII), so nothing could be cut without losing information.

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 five-parameter onboarding tool with full schema coverage and no output schema, the description covers the prerequisites, the content expected, the anti-hallucination instruction, and the cost. The only gap is sequencing against start_signup/finish_signup, which is modest given how explicit the rest is.

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 100%, so the baseline is 3; the description earns above baseline by adding a constraint the schema omits (exclude personal data) and by directing the agent to paraphrase in its own words rather than copy boilerplate. It also glosses the two core required inputs as 'what data' and 'what they want to do with it', which helps map intent to fields, though found_us, agent and details are left entirely to the schema.

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 states a concrete purpose: a one-time per-account onboarding step that records what data the user wants and why. 'Required once per account before the data tools work' makes the gating role explicit. It loses a point because it never distinguishes itself from the sibling signup tools start_signup and finish_signup, nor does it explain how the fields it collects relate to those flows.

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?

Strong when-to-use guidance: it must be called once per account before other data tools, it costs no quota, and the agent is told to ask the user rather than fabricate answers. What is missing is any exclusivity or ordering guidance relative to start_signup and finish_signup, which an agent could easily confuse with this tool.

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