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

Annotations only say this is a non-read-only, open-world, non-idempotent, non-destructive call; the description adds the substantive behavior: consent gating, an out-of-band e-mail confirmation click, external quote requests sent per make-part only after that click, and the returned project id/token. That is exactly the kind of side-effect and authorization detail structured fields cannot convey.

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 sentences, front-loaded with the action and outcome, with the consent gate stated before the return values. The parenthetical '(as plan_prototype)' is slightly dense but earns its place by linking to the sibling.

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?

With no output schema, the description usefully describes what comes back (project id, read token, plan) and covers the consent/confirmation workflow for a 6-parameter mutation. Minor gaps: it does not say what state the project enters afterward or how the token should be handled.

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 83%, so the schema already documents description, requester_email, user_consent and the optional fields. The description largely restates requester_email and user_consent requirements rather than adding new meaning (e.g. token handling, ship_to_country or budget_note behavior), so 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 ('Start a prototype project') and spells out the two-step outcome: build the sourcing plan (as plan_prototype) and then send one quote request per make-part to matched manufacturers. Naming plan_prototype inline distinguishes it from that sibling and from create_rfq, so an agent can tell them apart without opening a schema.

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 clear invocation context: use it for the human you act for, it needs requester e-mail and user_consent, and nothing is sent before the confirmation click. It implicitly routes plan-only needs to plan_prototype by naming it as the plan mechanism, but there is no explicit 'use X instead when...' exclusion for create_rfq or plan_prototype.

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